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1.
EMBO J ; 42(7): e111450, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-36861806

RESUMEN

Membrane ion channels of the calcium homeostasis modulator (CALHM) family promote cell-cell crosstalk at neuronal synapses via ATP release, where ATP acts as a neurotransmitter. CALHM6, the only CALHM highly expressed in immune cells, has been linked to the induction of natural killer (NK) cell anti-tumour activity. However, its mechanism of action and broader functions in the immune system remain unclear. Here, we generated Calhm6-/- mice and report that CALHM6 is important for the regulation of the early innate control of Listeria monocytogenes infection in vivo. We find that CALHM6 is upregulated in macrophages by pathogen-derived signals and that it relocates from the intracellular compartment to the macrophage-NK cell synapse, facilitating ATP release and controlling the kinetics of NK cell activation. Anti-inflammatory cytokines terminate CALHM6 expression. CALHM6 forms an ion channel when expressed in the plasma membrane of Xenopus oocytes, where channel opening is controlled by a conserved acidic residue, E119. In mammalian cells, CALHM6 is localised to intracellular compartments. Our results contribute to the understanding of neurotransmitter-like signal exchange between immune cells that fine-tunes the timing of innate immune responses.


Asunto(s)
Infecciones Bacterianas , Sinapsis Inmunológicas , Ratones , Animales , Canales Iónicos/metabolismo , Células Asesinas Naturales , Infecciones Bacterianas/metabolismo , Adenosina Trifosfato/metabolismo , Mamíferos
2.
Nat Methods ; 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38918605

RESUMEN

Contemporary pose estimation methods enable precise measurements of behavior via supervised deep learning with hand-labeled video frames. Although effective in many cases, the supervised approach requires extensive labeling and often produces outputs that are unreliable for downstream analyses. Here, we introduce 'Lightning Pose', an efficient pose estimation package with three algorithmic contributions. First, in addition to training on a few labeled video frames, we use many unlabeled videos and penalize the network whenever its predictions violate motion continuity, multiple-view geometry and posture plausibility (semi-supervised learning). Second, we introduce a network architecture that resolves occlusions by predicting pose on any given frame using surrounding unlabeled frames. Third, we refine the pose predictions post hoc by combining ensembling and Kalman smoothing. Together, these components render pose trajectories more accurate and scientifically usable. We released a cloud application that allows users to label data, train networks and process new videos directly from the browser.

3.
Blood ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38820498

RESUMEN

Interplay between platelets, coagulation factors, endothelial cells (ECs) and fibrinolytic factors is necessary for effective hemostatic plug formation. This study describes a four-dimensional (4D) imaging platform to visualize and quantify hemostatic plug components in mice with high spatiotemporal resolution. Fibrin accumulation following laser-induced vascular injury was observed at the platelet plug-EC interface, controlled by the antagonistic balance between fibrin generation and breakdown. We observed less fibrin accumulation in mice expressing low levels of tissue factor (TFlow) or F12-/- mice compared to controls, whereas increased fibrin accumulation, including on the vasculature adjacent to the platelet plug, was observed in plasminogen-deficient mice or wild-type mice treated with tranexamic acid (TXA). Phosphatidylserine (PS), a membrane lipid critical for the assembly of coagulation factors, was first detected at the platelet plug-EC interface, followed by exposure across the endothelium. Impaired PS exposure resulted in a significant reduction in fibrin accumulation in cyclophilin D-/- mice. Adoptive transfer studies demonstrated a key role for PS exposure on platelets, and to a lesser degree on ECs, in fibrin accumulation during hemostatic plug formation. Together, these studies suggest that (1) platelets are the functionally dominant procoagulant cellular surface, and (2) plasmin is critical for limiting fibrin accumulation at the site of a forming hemostatic plug.

4.
Blood ; 143(2): 105-117, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-37832029

RESUMEN

ABSTRACT: Elevated circulating fibrinogen levels correlate with increased risk for both cardiovascular and venous thromboembolic diseases. In vitro studies show that formation of a highly dense fibrin matrix is a major determinant of clot structure and stability. Here, we analyzed the impact of nonpolymerizable fibrinogen on arterial and venous thrombosis as well as hemostasis in vivo using FgaEK mice that express normal levels of a fibrinogen that cannot be cleaved by thrombin. In a model of carotid artery thrombosis, FgaWT/EK and FgaEK/EK mice were protected from occlusion with 4% ferric chloride (FeCl3) challenges compared with wild-type (FgaWT/WT) mice, but this protection was lost, with injuries driven by higher concentrations of FeCl3. In contrast, fibrinogen-deficient (Fga-/-) mice showed no evidence of occlusion, even with high-concentration FeCl3 challenge. Fibrinogen-dependent platelet aggregation and intraplatelet fibrinogen content were similar in FgaWT/WT, FgaWT/EK, and FgaEK/EK mice, consistent with preserved fibrinogen-platelet interactions that support arterial thrombosis with severe challenge. In an inferior vena cava stasis model of venous thrombosis, FgaEK/EK mice had near complete protection from thrombus formation. FgaWT/EK mice also displayed reduced thrombus incidence and a significant reduction in thrombus mass relative to FgaWT/WT mice after inferior vena cava stasis, suggesting that partial expression of nonpolymerizable fibrinogen was sufficient for conferring protection. Notably, FgaWT/EK and FgaEK/EK mice had preserved hemostasis in multiple models as well as normal wound healing times after skin incision, unlike Fga-/- mice that displayed significant bleeding and delayed healing. These findings indicate that a nonpolymerizable fibrinogen variant can significantly suppress occlusive thrombosis while preserving hemostatic potential in vivo.


Asunto(s)
Hemostáticos , Trombosis , Trombosis de la Vena , Animales , Ratones , Fibrinógeno/metabolismo , Hemostasis , Trombosis de la Vena/genética , Trombosis de la Vena/metabolismo , Trombosis/metabolismo , Plaquetas/metabolismo
5.
Nature ; 574(7776): 63-68, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31554967

RESUMEN

The gp130 receptor cytokines IL-6 and CNTF improve metabolic homeostasis but have limited therapeutic use for the treatment of type 2 diabetes. Accordingly, we engineered the gp130 ligand IC7Fc, in which one gp130-binding site is removed from IL-6 and replaced with the LIF-receptor-binding site from CNTF, fused with the Fc domain of immunoglobulin G, creating a cytokine with CNTF-like, but IL-6-receptor-dependent, signalling. Here we show that IC7Fc improves glucose tolerance and hyperglycaemia and prevents weight gain and liver steatosis in mice. In addition, IC7Fc either increases, or prevents the loss of, skeletal muscle mass by activation of the transcriptional regulator YAP1. In human-cell-based assays, and in non-human primates, IC7Fc treatment results in no signs of inflammation or immunogenicity. Thus, IC7Fc is a realistic next-generation biological agent for the treatment of type 2 diabetes and muscle atrophy, disorders that are currently pandemic.


Asunto(s)
Receptor gp130 de Citocinas/metabolismo , Citocinas/síntesis química , Citocinas/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inmunoglobulina G/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Unión Competitiva , Citocinas/química , Diabetes Mellitus Tipo 2/metabolismo , Diseño de Fármacos , Hígado Graso/prevención & control , Prueba de Tolerancia a la Glucosa , Humanos , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/metabolismo , Incretinas/metabolismo , Interleucina-6/antagonistas & inhibidores , Interleucina-6/metabolismo , Masculino , Ratones , Músculo Esquelético/efectos de los fármacos , Obesidad/metabolismo , Páncreas/metabolismo , Fosfoproteínas/metabolismo , Ingeniería de Proteínas , Receptores de Interleucina-6/metabolismo , Transducción de Señal , Factores de Transcripción , Aumento de Peso/efectos de los fármacos , Proteínas Señalizadoras YAP
6.
Circulation ; 147(17): 1264-1276, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-36866664

RESUMEN

BACKGROUND: Concerns have been raised about the long-term performance of aortic stent grafts for the treatment of abdominal aortic aneurysms, in particular, unibody stent grafts (eg, Endologix AFX AAA stent grafts). Only limited data sets are available to evaluate the long-term risks related to these devices. The SAFE-AAA Study (Comparison of Unibody and Non-Unibody Endografts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries Study) was designed with the Food and Drug Administration to provide a longitudinal assessment of the safety of unibody aortic stent grafts among Medicare beneficiaries. METHODS: The SAFE-AAA Study was a prespecified, retrospective cohort study evaluating whether unibody aortic stent grafts are noninferior to non-unibody aortic stent grafts with respect to the composite primary outcome of aortic reintervention, rupture, and mortality. Procedures were evaluated from August 1, 2011, through December 31, 2017. The primary end point was evaluated through December 31, 2019. Inverse probability weighting was used to account for imbalances in observed characteristics. Sensitivity analyses were used to evaluate the effect of unmeasured confounding, including assessment of the falsification end points heart failure, stroke, and pneumonia. A prespecified subgroup included patients treated from February 22, 2016, through December 31, 2017, corresponding to the market release of the most contemporary unibody aortic stent grafts (Endologix AFX2 AAA stent graft). RESULTS: Of 87 163 patients who underwent aortic stent grafting at 2146 US hospitals, 11 903 (13.7%) received a unibody device. The average age of the total cohort was 77.0±6.7 years, 21.1% were female, 93.5% were White, 90.8% had hypertension, and 35.8% used tobacco. The primary end point occurred in 73.4% of unibody device-treated patients versus 65.0% of non-unibody device-treated patients (hazard ratio, 1.19 [95% CI, 1.15-1.22]; noninferior P value of 1.00; median follow-up, 3.4 years). Falsification end points were negligibly different between groups. In the subgroup treated with contemporary unibody aortic stent grafts, the cumulative incidence of the primary end point occurred in 37.5% of unibody device-treated patients and 32.7% of non-unibody device-treated patients (hazard ratio, 1.06 [95% CI, 0.98-1.14]). CONCLUSIONS: In the SAFE-AAA Study, unibody aortic stent grafts failed to meet noninferiority compared with non-unibody aortic stent grafts with respect to aortic reintervention, rupture, and mortality. These data support the urgency of instituting a prospective longitudinal surveillance program for monitoring safety events related to aortic stent grafts.


Asunto(s)
Aneurisma de la Aorta Abdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Humanos , Femenino , Anciano , Estados Unidos , Anciano de 80 o más Años , Masculino , Prótesis Vascular , Implantación de Prótesis Vascular/efectos adversos , Estudios Retrospectivos , Estudios Prospectivos , Resultado del Tratamiento , Procedimientos Endovasculares/efectos adversos , Medicare , Stents , Diseño de Prótesis
7.
Blood ; 139(21): 3194-3203, 2022 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-35358299

RESUMEN

Platelets are critical in hemostasis and a major contributor to arterial thrombosis (AT). (Pre)clinical studies suggest platelets also contribute to venous thrombosis (VT), but the mechanisms are largely unknown. We hypothesized that in VT, platelets use signaling machinery distinct from AT. Here we aimed to characterize the contributions of platelet G protein-coupled (GPCR) and immunoreceptor tyrosine-based activation motif (ITAM) receptor signaling to VT. Wild-type (WT) and transgenic mice were treated with inhibitors to selectively inhibit platelet-signaling pathways: ITAM-CLEC2 (Clec2mKO), glycoprotein VI (JAQ1 antibody), and Bruton's tyrosine kinase (ibrutinib); GPCR-cyclooxygenase 1 (aspirin); and P2Y12 (clopidogrel). VT was induced by inferior vena cava stenosis. Thrombin generation in platelet-rich plasma and whole-blood clot formation were studied ex vivo. Intravital microscopy was used to study platelet-leukocyte interactions after flow restriction. Thrombus weights were reduced in WT mice treated with high-dose aspirin + clopidogrel (dual antiplatelet therapy [DAPT]) but not in mice treated with either inhibitor alone or low-dose DAPT. Similarly, thrombus weights were reduced in mice with impaired ITAM signaling (Clec2mKO + JAQ1; WT + ibrutinib) but not in Clec2mKO or WT + JAQ1 mice. Both aspirin and clopidogrel, but not ibrutinib, protected mice from FeCl3-induced AT. Thrombin generation and clot formation were normal in blood from high-dose DAPT- or ibrutinib-treated mice; however, platelet adhesion and platelet-neutrophil aggregate formation at the vein wall were reduced in mice treated with high-dose DAPT or ibrutinib. In summary, VT initiation requires platelet activation via GPCRs and ITAM receptors. Strong inhibition of either signaling pathway reduces VT in mice.


Asunto(s)
Trombosis , Trombosis de la Vena , Animales , Aspirina , Plaquetas/metabolismo , Clopidogrel/metabolismo , Clopidogrel/farmacología , Proteínas de Unión al GTP , Motivo de Activación del Inmunorreceptor Basado en Tirosina , Ratones , Ratones Transgénicos , Activación Plaquetaria , Agregación Plaquetaria , Inhibidores de Agregación Plaquetaria/farmacología , Trombina/metabolismo , Trombosis/metabolismo , Trombosis de la Vena/metabolismo
8.
Blood ; 139(16): 2523-2533, 2022 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-35157766

RESUMEN

Microvascular thrombosis in patients with thrombotic thrombocytopenic purpura (TTP) is initiated by GPIbα-mediated platelet binding to von Willebrand factor (VWF). Binding of VWF to GPIbα causes activation of the platelet surface integrin αIIbß3. However, the mechanism of GPIbα-initiated activation of αIIbß3 and its clinical importance for microvascular thrombosis remain elusive. Deletion of platelet C-type lectin-like receptor 2 (CLEC-2) did not prevent VWF binding to platelets but specifically inhibited platelet aggregation induced by VWF binding in mice. Deletion of platelet CLEC-2 also inhibited αIIbß3 activation induced by the binding of VWF to GPIbα. Using a mouse model of TTP, which was created by infusion of anti-mouse ADAMTS13 monoclonal antibodies followed by infusion of VWF, we found that deletion of platelet CLEC-2 decreased pulmonary arterial thrombosis and the severity of thrombocytopenia. Importantly, prophylactic oral administration of aspirin, an inhibitor of platelet activation, and therapeutic treatment of the TTP mice with eptifibatide, an integrin αIIbß3 antagonist, reduced pulmonary arterial thrombosis in the TTP mouse model. Our observations demonstrate that GPIbα-mediated activation of integrin αIIbß3 plays an important role in the formation of thrombosis in TTP. These observations suggest that prevention of platelet activation with aspirin may reduce the risk for thrombosis in patients with TTP.


Asunto(s)
Hipertensión Pulmonar , Púrpura Trombocitopénica Trombótica , Trombosis , Aspirina , Plaquetas/metabolismo , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Activación Plaquetaria , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Púrpura Trombocitopénica Trombótica/metabolismo , Trombosis/etiología , Factor de von Willebrand/metabolismo
9.
Brain Behav Immun ; 119: 919-944, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38718909

RESUMEN

Neuroinflammation and accumulation of Amyloid Beta (Aß) accompanied by deterioration of special memory are hallmarks of Alzheimer's disease (AD). Effective preventative and treatment options for AD are still needed. Microglia in AD brains are characterized by elevated levels of microRNA-17 (miR-17), which is accompanied by defective autophagy, Aß accumulation, and increased inflammatory cytokine production. However, the effect of targeting miR-17 on AD pathology and memory loss is not clear. To specifically inhibit miR-17 in microglia, we generated mannose-coated lipid nanoparticles (MLNPs) enclosing miR-17 antagomir (Anti-17 MLNPs), which are targeted to mannose receptors readily expressed on microglia. We used a 5XFAD mouse model (AD) that recapitulates many AD-related phenotypes observed in humans. Our results show that Anti-17 MLNPs, delivered to 5XFAD mice by intra-cisterna magna injection, specifically deliver Anti-17 to microglia. Anti-17 MLNPs downregulated miR-17 expression in microglia but not in neurons, astrocytes, and oligodendrocytes. Anti-17 MLNPs attenuated inflammation, improved autophagy, and reduced Aß burdens in the brains. Additionally, Anti-17 MLNPs reduced the deterioration in spatial memory and decreased anxiety-like behavior in 5XFAD mice. Therefore, targeting miR-17 using MLNPs is a viable strategy to prevent several AD pathologies. This selective targeting strategy delivers specific agents to microglia without the adverse off-target effects on other cell types. Additionally, this approach can be used to deliver other molecules to microglia and other immune cells in other organs.


Asunto(s)
Enfermedad de Alzheimer , Encéfalo , Modelos Animales de Enfermedad , Manosa , Ratones Transgénicos , MicroARNs , Microglía , Nanopartículas , Animales , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , MicroARNs/metabolismo , Nanopartículas/administración & dosificación , Ratones , Microglía/metabolismo , Microglía/efectos de los fármacos , Manosa/farmacología , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Péptidos beta-Amiloides/metabolismo , Lípidos , Masculino , Antagomirs/farmacología , Antagomirs/administración & dosificación
10.
J Org Chem ; 89(1): 484-497, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38143311

RESUMEN

The direct transformation of 1,3-dienes into valuable 2,5-diarylfurans using transition-metal-free conditions is presented. By employing a simple oxidation─dehydration sequence on readily accessible 1,3-dienes, important 2,5-diarylfuran building blocks frequently used in medicinal and material chemistry are prepared. The oxidation step is realized using singlet oxygen, and the intermediate endoperoxide is dehydrated under metal-free conditions and at ambient temperature using the Appel reagent. Notably, this sequence can be streamlined into continuous flow, thereby eliminating the isolation of the intermediate, often unstable endoperoxide. This leads to a significant improvement in isolated yields (ca. 27% average increase) of the 2,5-diarylfurans while also increasing safety and reducing waste. Our transition-metal-free synthetic approach to 2,5-diarylfurans delivers several important furan building blocks used commonly in medicinal chemistry and as optoelectronic materials, including short-chain linearly conjugated furan oligomers. Consequently, we also complete a short study of the optical and electrochemical properties of a selection of these novel materials.

11.
Respirology ; 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38806394

RESUMEN

BACKGROUND AND OBJECTIVE: Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB. METHODS: Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models. RESULTS: A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 µSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose. CONCLUSION: The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.

12.
Cytopathology ; 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38814131

RESUMEN

OBJECTIVES: Comprehensive molecular analysis for patients with non-small-cell lung carcinoma (NSCLC) is essential for managing modern targeted therapies. This study sought to establish the feasibility of utilising real-time PCR to perform rapid and comprehensive profiling on minimal amounts of endobronchial ultrasound-guided (EBUS) aspirates as a fast, tissue-sparing route of predictive profiling. METHODS: A volume of 500 µL of EBUS aspirate and fixative from patients with NSCLC was decanted, and 80 µL (<1% of total specimen received) was utilised for analysis. Biocartis Idylla™ cartridges for epidermal growth factor receptor (EGFR) mutations, KRAS mutations and a GeneFusion cartridge (ALK, ROS1, RET, NTRK1/2/3 rearrangements & MET 14 exon skipping) were analysed for each case to provide molecular data on the main clinically relevant targets as per UK guidelines. RESULTS: A total of 62 cases were included; all of which had successful DNA analysis (EGFR and KRAS cartridges). RNA analysis (GeneFusion cartridge) was successful for 42 of 51 (82%) with initial approach, with 11 of 11 (100%) achieving a successful result with modified protocol. In all, 23 KRAS mutations (37%), 5 EGFR mutations (8%) and 1 ROS fusion (2%) were identified. Average time from specimen receipt to molecular read-out was 5 h. CONCLUSION: Real-time PCR utilising the Idylla™ platform is rapid, utilises minimal amounts of tissue and provides accurate results. We propose this is a useful ancillary method to utilise alongside next-generation sequencing (NGS) in cases of urgent clinical requirement or EBUS aspirates with inadequate quantities of tissue for NGS.

13.
Drug Dev Ind Pharm ; 50(4): 297-305, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38385210

RESUMEN

OBJECTIVE: This study aimed to investigate the impact of physical solid dispersions of spray-dried glibenclamide (SG) on the surface of microcrystalline cellulose (MC) and mannitol (M) surfaces, as well as their combination with phosphatidylcholine (P), on enhancing the dissolution rate of glibenclamide (G). METHODS: Solid dispersions were prepared using varying proportions of 1:1, 1:4, and 1:10 for SG on the surface of MC (SGA) and M (SGM), and then combined with P, in a proportion of 1:4:0.02 using spray drying. The particle size, specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and dissolution rate of SGA and SGM were characterized. RESULTS: SEM analysis revealed successful adhesion of SG onto the surface of the carrier surfaces. XRD showed reduced crystalline characteristic peaks for SGA, while SGM exhibited a sharp peaks pattern. Both SGA and SGM demonstrated higher dissolution rates compared to SG and G alone. Furthermore, the dissolution rates of the solid dispersions of SG, MC and P (SGAP), and SG, M, and P (SGMP) were sequentially higher than that of SGA and SGM. CONCLUSIONS: The study suggests that physical solid dispersions of SG on MC and M, along with their combination with P, can effectively enhance the dissolution rate of G. These findings may be valuable in developing of oral solid drug dosage forms utilizing SGA, SGM, SGAP, and SGMP.


Asunto(s)
Celulosa , Gliburida , Manitol , Fosfatidilcolinas , Solubilidad , Difracción de Rayos X , Rastreo Diferencial de Calorimetría
14.
Blood ; 137(20): 2756-2769, 2021 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-33619517

RESUMEN

During early embryonic development in mammals, including humans and mice, megakaryocytes (Mks) first originate from primitive hematopoiesis in the yolk sac. These embryonic Mks (eMks) circulate in the vasculature with unclear function. Herein, we report that podoplanin (PDPN), the ligand of C-type lectin-like receptor (CLEC-2) on Mks/platelets, is temporarily expressed in neural tissue during midgestation in mice. Loss of PDPN or CLEC-2 resulted in aneurysms and spontaneous hemorrhage, specifically in the lower diencephalon during midgestation. Surprisingly, more eMks/platelets had enhanced granule release and localized to the lower diencephalon in mutant mouse embryos than in wild-type littermates before hemorrhage. We found that PDPN counteracted the collagen-1-induced secretion of angiopoietin-1 from fetal Mks, which coincided with enhanced TIE-2 activation in aneurysm-like sprouts of PDPN-deficient embryos. Blocking platelet activation prevented the PDPN-deficient embryo from developing vascular defects. Our data reveal a new role for PDPN in regulating eMk function during midgestation.


Asunto(s)
Encéfalo/irrigación sanguínea , Aneurisma Intracraneal/etiología , Megacariocitos/patología , Glicoproteínas de Membrana/deficiencia , Aneurisma Roto/embriología , Aneurisma Roto/etiología , Angiopoyetina 1/metabolismo , Animales , Encéfalo/embriología , Células Cultivadas , Hemorragia Cerebral/embriología , Hemorragia Cerebral/etiología , Colágeno/farmacología , Diencéfalo/irrigación sanguínea , Diencéfalo/embriología , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Aneurisma Intracraneal/embriología , Aneurisma Intracraneal/genética , Aneurisma Intracraneal/patología , Lectinas Tipo C/deficiencia , Lectinas Tipo C/genética , Lectinas Tipo C/fisiología , Megacariocitos/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiología , Ratones , Ratones Noqueados , Neovascularización Patológica/genética , Neovascularización Patológica/fisiopatología , Neovascularización Fisiológica/fisiología , Activación Plaquetaria , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Receptor TIE-2/metabolismo
15.
Mol Pharm ; 20(4): 1951-1963, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-36952242

RESUMEN

Hepatocellular carcinoma (HCC) is one of the most common cancers, with high mortality. Chemotherapy is one of the main treatment options for HCC. However, the high toxicity and poor specificity of chemotherapeutic drugs have limited their clinical application. In this study, dual-ligand liposomes modified with glycyrrhetinic acid (GA) and cyclic arginine-glycine-aspartic acid (cRGD) (GA/cRGD-LP) were designed to target the GA receptor and αvß3 integrin, respectively. The aim was to develop a highly selective targeted drug delivery system and further enhance the antitumor efficiency of drugs by targeting both hepatic tumor cells and vasculature. A novel lipid conjugate (mGA-DOPE) by coupling dioleoylphosphatidyl ethanolamine (DOPE) with methyl glycyrrhetinic acid (mGA) was synthesized, and its structure was confirmed. The targeting efficiency of GA/cRGD-LP by in vitro cellular uptake and ex vivo imaging was assessed. GA- and cRGD-modified doxorubicin-loaded liposomes (GA/cRGD-LP-DOX) were prepared, and their cytotoxicity in HepG2 and antitumor activity were evaluated. The results showed that the average particle size of the GA/cRGD-LP-DOX was 114 ± 4.3 nm, and the zeta potential was -32.9 ± 2.0 mV. The transmission electron microscopy images showed that the shapes of our liposomes were spherical. cGA/cRGD-LP-DOX displayed an excellent cellular uptake in both HepG2 and human umbilical vein endothelial cells. In the in vivo study, pharmacokinetic parameters indicated that cGA/cRGD-LP can prolong the circulation time of DOX in the blood. GA/cRGD-LP-DOX showed greater inhibition of tumor growth for HepG2-bearing mice than either the single-ligand-modified liposomes or nontargeted liposomes. GA/cRGD-LP-DOX displayed higher liver tumor localization than that of single-ligand-modified liposomes or free DOX. GA/cRGD-LP is a promising drug delivery system for liver cancer targeting and therapy and is worthy of further study.


Asunto(s)
Carcinoma Hepatocelular , Ácido Glicirretínico , Neoplasias Hepáticas , Humanos , Ratones , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Liposomas/química , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Ligandos , Ácido Glicirretínico/química , Células Endoteliales , Doxorrubicina , Línea Celular Tumoral
16.
Phytopathology ; 113(2): 265-276, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35984372

RESUMEN

Ascochyta blight is a damaging disease that affects the stems, leaves, and pods of field pea (Pisum sativum) and impacts yield and grain quality. In Australia, field pea Ascochyta blight is primarily caused by the necrotrophic fungal species Peyronellaea pinodes and Ascochyta koolunga. In this study, we screened 1,276 Pisum spp. germplasm accessions in seedling disease assays with a mix of three isolates of P. pinodes and 641 accessions with three mixed isolates of A. koolunga (513 accessions were screened with both species). A selection of three P. sativum accessions with low disease scores for either pathogen, or in some cases both, were crossed with Australian field pea varieties PBA Gunyah and PBA Oura, and recombinant inbred line populations were made. Populations at the F3:4 and F4:5 generation were phenotyped for their disease response to P. pinodes and A. koolunga, and genotypes were determined using the diversity arrays technology genotyping method. Marker-trait associations were identified using a genome-wide association study approach. Trait-associated loci were mapped to the published P. sativum genome assembly, and candidate resistance gene analogues were identified in the corresponding genomic regions. One locus on chromosome 2 (LG1) was associated with resistance to P. pinodes, and the 8 Mb genomic region contains 156 genes, two of which are serine/threonine protein kinases, putatively contributing to the resistance trait. A second locus on chromosome 5 (LG3) was associated with resistance to A. koolunga, and the 35 Mb region contains 488 genes, of which five are potential candidate resistance genes, including protein kinases, a mitogen-activated protein kinase, and an ethylene-responsive protein kinase homolog.


Asunto(s)
Estudio de Asociación del Genoma Completo , Pisum sativum , Pisum sativum/genética , Pisum sativum/microbiología , Plantones/genética , Australia , Enfermedades de las Plantas/microbiología
17.
Phytopathology ; 113(8): 1515-1524, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36935379

RESUMEN

Ascochyta lentis, the causal organism of Ascochyta blight (AB) of lentil (Lens culinaris), has been shown to produce an avirulence effector protein that mediates AB resistance in certain lentil cultivars. The two known forms of the effector protein were identified from a biparental mapping population between isolates that have reciprocal virulence on 'PBA Hurricane XT' and 'Nipper'. The effector AlAvr1-1 was described for the PBA Hurricane XT-avirulent isolate P94-24 and AlAvr1-2 characterized in the PBA Hurricane XT-virulent isolate AlKewell. Here, we performed a genome-wide association study to identify other loci associated with AB for a differential set of lentil cultivars from a diverse panel of isolates collected in the Australian lentil-growing regions from 2013 to 2020. The chromosome 3 AlAvr1 locus was strongly associated with the PBA Hurricane XT, 'Indianhead', and Nipper disease responses, but one other genomic region on chromosome 11 was also associated with the Nipper disease trait. Our results corroborate earlier work that identified the AlAvr1 locus for field-collected isolates that span the period before release and after widespread adoption of PBA Hurricane XT. A multiplex PCR assay was developed to differentiate the genes AlAvr1-1 and AlAvr1-2 to predict PBA Hurricane XT avirulence and pathotype designation in the diversity panel. Increasing numbers of the PBA Hurricane XT-virulent pathotype 2 isolates across that time indicate strong selection for isolates with the AlAvr1-2 allele. Furthermore, one other region of the A. lentis genome may contribute to the pathogen-host interaction for lentil AB.

18.
Platelets ; 34(1): 2157383, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36683325

RESUMEN

Circulating platelets maintain low cytosolic Ca2+ concentrations. At sites of vascular injury, agonist-induced Ca2+ release from platelet intracellular stores triggers influx of extracellular Ca2+, a process known as store-operated Ca2+ entry (SOCE). Stromal interaction molecule 1 (Stim1) senses reduced Ca2+ stores and triggers SOCE. Gain-of-function (GOF) mutations in Stim1, such as described for Stormorken syndrome patients or mutant mice (Stim1Sax), are associated with marked thrombocytopenia and increased platelet turnover. We hypothesized that reduced platelet survival in Stim1Sax/+ mice is due to increased Rap1/integrin signaling and platelet clearance in the spleen, similar to what we recently described for mice expressing a mutant version of the Rap1-GAP, Rasa3 (Rasa3hlb/hlb). Stim1Sax/+ mice were crossed with mice deficient in CalDAG-GEFI, a critical calcium-regulated Rap1-GEF in platelets. In contrast to Rasa3hlb/hlb x Caldaggef1-/- mice, only a small increase in the peripheral platelet count, but not platelet lifespan, was observed in Stim1Sax/+ x Caldaggef1-/- mice. Similarly, inhibition of αIIbß3 integrin in vivo only minimally raised the peripheral platelet count in Stim1Sax/+ mice. Compared to controls, Stim1Sax/+ mice exhibited increased platelet accumulation in the lung, but not the spleen or liver. These results suggest that CalDAG-GEFI/Rap1/integrin signaling contributes only minimally to accelerated platelet turnover caused by constitutive SOCE.


What do we know? Platelets are small blood cells which act to prevent blood loss, which circulate in a resting state but are rapidly activated upon exposure to ligands at the site of vascular injuryCalcium (Ca2+) is critical for platelet activation, especially for activation of integrins which support platelet­platelet interactionsIf platelet activation occurs in circulation, platelets can be prematurely cleared from blood and unable to function in hemostasisDisorders of Ca2+ dysregulation such as Stormorken syndrome are associated with reduced platelet counts (thrombocytopenia) and bleedingWhat did we discover? We used a mouse model expressing a mutation causing higher Ca2+ levels in cells including platelets (Stim1Sax), and investigated whether thrombocytopenia is due to stimulation of a specific pathway for integrin activation, mediated by a protein called Rap1 GTPaseWe crossed Stim1Sax mice with mice lacking an important activator of Rap1, the Ca2+-regulated protein CalDAG-GEFI, and saw no major improvement in thrombocytopeniaWe also observed more Stim1Sax platelets in the lung but not the liver or spleen, in contrast to mice with activation of platelet integrins in circulationWhat is the impact? Our results rule out activation of the CalDAG-GEFI/Rap1/integrin pathway as a major cause of thrombocytopenia in Stim1Sax miceOur findings help to narrow down potential causes of thrombocytopenia in disorders such as Stormorken syndrome.


Asunto(s)
Plaquetas , Calcio , Factores de Intercambio de Guanina Nucleótido , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria , Animales , Ratones , Plaquetas/metabolismo , Calcio/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Transducción de Señal , Trombocitopenia/sangre , Trombocitopenia/metabolismo
19.
Lung ; 201(1): 85-93, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36695890

RESUMEN

BACKGROUND: Transbronchial lung biopsy with radial endobronchial ultrasound (rEBUS-TBB) and Computed tomography (CT) scan-guided transthoracic biopsy (CT-TTB) are commonly used to investigate peripheral lung nodules but high-quality data are still not clear about the diagnostic and safety profile comparison of these two modalities. METHOD: We included all randomized controlled trials (RCT) comparing rEBUS-TBB with a flexible bronchoscope and CT-TTB for solitary lung nodules. Two reviewers extracted data independently on diagnostic performance and complication rates. RESULTS: 170 studies were screened, 4 RCT with a total of 325 patients were included. CT-TTB had a higher diagnostic yield than rEBUS-TBB (83.45% vs 68.82%, risk difference - 0.15, 95% CI, [- 0.24, - 0.05]), especially for lesion size 1-2 cm (83% vs 50%, risk difference - 0.33, 95% CI, [- 0.51, - 0.14]). For malignant diseases, rEBUS-TBB had a diagnostic yield of 75.75% vs 87.7% of CT-TTB. rEBUS-TBB had a significant better safety profile with lower risks of pneumothorax (2.87% vs 21.43%, OR = 0.12, 95% CI [0.05-0.32]) and combined outcomes of hospital admission, hemorrhage, and pneumothorax (8.62% vs 31.81%, OR 0.21, 95% CI, [0.11-0.40]). Factors increasing diagnostic yield of rEBUS were lesion size and localization of the probe but not the distance to the chest wall and hilum. CONCLUSION: CT-TTB had a higher diagnostic yield than rEBUS-TBB in diagnosing peripheral lung nodules, particularly for lesions from 1 to 2 cm. However, rEBUS-TBB was significantly safer with five to eight times less risk of pneumothorax and composite complications of hospital admission, hemorrhage, and pneumothorax. The results of this study only apply to flexible bronchoscopy with radial ebus without navigational technologies. More data are needed for a comparison between CT-TTB with rEBUS-TBB combined with advanced navigational modalities.


Asunto(s)
Neoplasias Pulmonares , Neumotórax , Nódulo Pulmonar Solitario , Humanos , Biopsia/efectos adversos , Broncoscopios/efectos adversos , Broncoscopía/efectos adversos , Endosonografía/efectos adversos , Hemorragia , Biopsia Guiada por Imagen/efectos adversos , Neoplasias Pulmonares/patología , Neumotórax/etiología , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos
20.
J Med Internet Res ; 25: e43658, 2023 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-37999957

RESUMEN

There are over 8 million central venous access devices inserted each year, many in patients with chronic conditions who rely on central access for life-preserving therapies. Central venous access device-related complications can be life-threatening and add tens of billions of dollars to health care costs, while their incidence is most likely grossly mis- or underreported by medical institutions. In this communication, we review the challenges that impair retention, exchange, and analysis of data necessary for a meaningful understanding of critical events and outcomes in this clinical domain. The difficulty is not only with data extraction and harmonization from electronic health records, national surveillance systems, or other health information repositories where data might be stored. The problem is that reliable and appropriate data are not recorded, or falsely recorded, at least in part because policy, payment, penalties, proprietary concerns, and workflow burdens discourage completeness and accuracy. We provide a roadmap for the development of health care information systems and infrastructure that address these challenges, framed within the context of research studies that build a framework of standardized terminology, decision support, data capture, and information exchange necessary for the task. This roadmap is embedded in a broader Coordinated Registry Network Learning Community, and facilitated by the Medical Device Epidemiology Network, a Public-Private Partnership sponsored by the US Food and Drug Administration, with the scope of advancing methods, national and international infrastructure, and partnerships needed for the evaluation of medical devices throughout their total life cycle.


Asunto(s)
Costos de la Atención en Salud , Atención Dirigida al Paciente , Humanos , Comunicación , Sistema de Registros
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