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1.
Nat Commun ; 15(1): 4857, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38849365

RESUMEN

Reticulocyte-binding protein homologue 5 (RH5), a leading blood-stage Plasmodium falciparum malaria vaccine target, interacts with cysteine-rich protective antigen (CyRPA) and RH5-interacting protein (RIPR) to form an essential heterotrimeric "RCR-complex". We investigate whether RCR-complex vaccination can improve upon RH5 alone. Using monoclonal antibodies (mAbs) we show that parasite growth-inhibitory epitopes on each antigen are surface-exposed on the RCR-complex and that mAb pairs targeting different antigens can function additively or synergistically. However, immunisation of female rats with the RCR-complex fails to outperform RH5 alone due to immuno-dominance of RIPR coupled with inferior potency of anti-RIPR polyclonal IgG. We identify that all growth-inhibitory antibody epitopes of RIPR cluster within the C-terminal EGF-like domains and that a fusion of these domains to CyRPA, called "R78C", combined with RH5, improves the level of in vitro parasite growth inhibition compared to RH5 alone. These preclinical data justify the advancement of the RH5.1 + R78C/Matrix-M™ vaccine candidate to Phase 1 clinical trial.


Asunto(s)
Anticuerpos Monoclonales , Anticuerpos Antiprotozoarios , Antígenos de Protozoos , Vacunas contra la Malaria , Malaria Falciparum , Plasmodium falciparum , Proteínas Protozoarias , Vacunas contra la Malaria/inmunología , Vacunas contra la Malaria/administración & dosificación , Animales , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Femenino , Malaria Falciparum/prevención & control , Malaria Falciparum/inmunología , Malaria Falciparum/parasitología , Antígenos de Protozoos/inmunología , Ratas , Anticuerpos Antiprotozoarios/inmunología , Anticuerpos Monoclonales/inmunología , Humanos , Epítopos/inmunología , Proteínas Portadoras/inmunología , Proteínas Portadoras/metabolismo
2.
Lancet Infect Dis ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38880111

RESUMEN

BACKGROUND: A blood-stage Plasmodium falciparum malaria vaccine would provide a second line of defence to complement partially effective or waning immunity conferred by the approved pre-erythrocytic vaccines. RH5.1 is a soluble protein vaccine candidate for blood-stage P falciparum, formulated with Matrix-M adjuvant to assess safety and immunogenicity in a malaria-endemic adult and paediatric population for the first time. METHODS: We did a non-randomised, phase 1b, single-centre, dose-escalation, age de-escalation, first-in-human trial of RH5.1/Matrix-M in Bagamoyo, Tanzania. We recruited healthy adults (aged 18-45 years) and children (aged 5-17 months) to receive the RH5.1/Matrix-M vaccine candidate in the following three-dose regimens: 10 µg RH5.1 at 0, 1, and 2 months (Adults 10M), and the higher dose of 50 µg RH5.1 at 0 and 1 month and 10 µg RH5.1 at 6 months (delayed-fractional third dose regimen; Adults DFx). Children received either 10 µg RH5.1 at 0, 1, and 2 months (Children 10M) or 10 µg RH5.1 at 0, 1, and 6 months (delayed third dose regimen; Children 10D), and were recruited in parallel, followed by children who received the dose-escalation regimen (Children DFx) and children with higher malaria pre-exposure who also received the dose-escalation regimen (High Children DFx). All RH5.1 doses were formulated with 50 µg Matrix-M adjuvant. Primary outcomes for vaccine safety were solicited and unsolicited adverse events after each vaccination, along with any serious adverse events during the study period. The secondary outcome measures for immunogenicity were the concentration and avidity of anti-RH5.1 serum IgG antibodies and their percentage growth inhibition activity (GIA) in vitro, as well as cellular immunogenicity to RH5.1. All participants receiving at least one dose of vaccine were included in the primary analyses. This trial is registered at ClinicalTrials.gov, NCT04318002, and is now complete. FINDINGS: Between Jan 25, 2021, and April 15, 2021, we recruited 12 adults (six [50%] in the Adults 10M group and six [50%] in the Adults DFx group) and 48 children (12 each in the Children 10M, Children 10D, Children DFx, and High Children DFx groups). 57 (95%) of 60 participants completed the vaccination series and 55 (92%) completed 22 months of follow-up following the third vaccination. Vaccinations were well-tolerated across both age groups. There were five serious adverse events involving four child participants during the trial, none of which were deemed related to vaccination. RH5-specific T cell and serum IgG antibody responses were induced by vaccination and purified total IgG showed in vitro GIA against P falciparum. We found similar functional quality (ie, GIA per µg RH5-specific IgG) across all age groups and dosing regimens at 14 days after the final vaccination; the concentration of RH5.1-specific polyclonal IgG required to give 50% GIA was 14·3 µg/mL (95% CI 13·4-15·2). 11 children were vaccinated with the delayed third dose regimen and showed the highest median anti-RH5 serum IgG concentration 14 days following the third vaccination (723 µg/mL [IQR 511-1000]), resulting in all 11 who received the full series showing greater than 60% GIA following dilution of total IgG to 2·5 mg/mL (median 88% [IQR 81-94]). INTERPRETATION: The RH5.1/Matrix-M vaccine candidate shows an acceptable safety and reactogenicity profile in both adults and 5-17-month-old children residing in a malaria-endemic area, with all children in the delayed third dose regimen reaching a level of GIA previously associated with protective outcome against blood-stage P falciparum challenge in non-human primates. These data support onward efficacy assessment of this vaccine candidate against clinical malaria in young African children. FUNDING: The European and Developing Countries Clinical Trials Partnership; the UK Medical Research Council; the UK Department for International Development; the National Institute for Health and Care Research Oxford Biomedical Research Centre; the Division of Intramural Research, National Institute of Allergy and Infectious Diseases; the US Agency for International Development; and the Wellcome Trust.

4.
Front Rehabil Sci ; 5: 1302179, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38450206

RESUMEN

Introduction: Early stakeholder engagement is critical to the successful development and translation of rehabilitation technologies, a pivotal step of which is usability testing with intended end-users. To this end, several methods employ end-user feedback to identify usability and implementation issues. However, the process of prioritizing identified issues seldom leverages the knowledge and expertise of the range of stakeholders who will ultimately affect the demand and supply of a device. This paper describes a novel method to prioritize end-user feedback using transdisciplinary stakeholder consultation and address it in subsequent product development. The proposed approach was demonstrated using a case study relating to the development of a novel technology for neural recovery after spinal cord injury. Method: Feedback from five individuals with chronic spinal cord injury was collected during two-hour usability evaluation sessions with a fully functional high-fidelity system prototype. A think-aloud and semi-structured interview protocol was used with each participant to identify usability and acceptability issues relating to the system in a 3-phase approach. Phase 1 involved extracting usability issues from think-aloud and semi-structured interview data. Phase 2 involved rating the usability issues based on their significance, technical feasibility, and implementation priority by relevant internal and external stakeholders. Finally, Phase 3 involved aggregating the usability issues according to design and implementation elements to facilitate solution generation, and these solutions were then raised as action tasks for future design iterations. Results: Sixty usability issues representing nine facets of usability were rated. Eighty percent of issues were rated to be of moderate to high significance, 83% were rated as being feasible to address, and 75% were rated as addressable using existing project resources. Fifty percent of the issues were rated to be a high priority for implementation. Evaluation of the grouped issues identified 21 tasks which were mapped to the product roadmap for integration into future design iterations. Discussion: This paper presents a method for meaningful transdisciplinary stakeholder engagement in rehabilitation technology development that can extended to other projects. Alongside a worked example, we offer practical considerations for others seeking to co-develop rehabilitation technologies.

5.
bioRxiv ; 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38464060

RESUMEN

Vascular inflammation critically regulates endothelial cell (EC) pathophenotypes, particularly in pulmonary arterial hypertension (PAH). Dysregulation of lysosomal activity and cholesterol metabolism have known inflammatory roles in disease, but their relevance to PAH is unclear. In human pulmonary arterial ECs and in PAH, we found that inflammatory cytokine induction of the nuclear receptor coactivator 7 (NCOA7) both preserved lysosomal acidification and served as a homeostatic brake to constrain EC immunoactivation. Conversely, NCOA7 deficiency promoted lysosomal dysfunction and proinflammatory oxysterol/bile acid generation that, in turn, contributed to EC pathophenotypes. In vivo, mice deficient for Ncoa7 or exposed to the inflammatory bile acid 7α-hydroxy-3-oxo-4-cholestenoic acid (7HOCA) displayed worsened PAH. Emphasizing this mechanism in human PAH, an unbiased, metabolome-wide association study (N=2,756) identified a plasma signature of the same NCOA7-dependent oxysterols/bile acids associated with PAH mortality (P<1.1x10-6). Supporting a genetic predisposition to NCOA7 deficiency, in genome-edited, stem cell-derived ECs, the common variant intronic SNP rs11154337 in NCOA7 regulated NCOA7 expression, lysosomal activity, oxysterol/bile acid production, and EC immunoactivation. Correspondingly, SNP rs11154337 was associated with PAH severity via six-minute walk distance and mortality in discovery (N=93, P=0.0250; HR=0.44, 95% CI [0.21-0.90]) and validation (N=630, P=2x10-4; HR=0.49, 95% CI [0.34-0.71]) cohorts. Finally, utilizing computational modeling of small molecule binding to NCOA7, we predicted and synthesized a novel activator of NCOA7 that prevented EC immunoactivation and reversed indices of rodent PAH. In summary, we have established a genetic and metabolic paradigm and a novel therapeutic agent that links lysosomal biology as well as oxysterol and bile acid processes to EC inflammation and PAH pathobiology. This paradigm carries broad implications for diagnostic and therapeutic development in PAH and in other conditions dependent upon acquired and innate immune regulation of vascular disease.

6.
Methods Mol Biol ; 2758: 49-60, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549007

RESUMEN

Neuropeptides are bioactive peptides that are synthesized and secreted by neurons in signaling pathways in the brain. Peptides and proteins are extremely vulnerable to proteolytic cleavage when their biological surrounding changes. This makes neuropeptidomics challenging due to the rapid alterations that occur to the peptidome after harvesting of brain tissue samples. For a successful neuropeptidomic study, the biological tissue sample analyzed should resemble the living state as much as possible. Heat stabilization has been proven to inhibit postmortem degradation by denaturing proteolytic enzymes, hence increasing identification rates of neuropeptides. Here, we describe two different stabilization protocols for rodent brain samples that increase the number of intact mature neuropeptides and minimize interference from degradation products of abundant proteins. Additionally, we present an extraction protocol that aims to extract a wide range of hydrophilic and hydrophobic neuropeptides by sequentially using an aqueous and an organic extraction medium.


Asunto(s)
Neuropéptidos , Neuropéptidos/metabolismo , Péptidos/metabolismo , Proteolisis , Péptido Hidrolasas/metabolismo , Encéfalo/metabolismo
7.
Methods Mol Biol ; 2758: 109-124, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549011

RESUMEN

A number of different approaches have been used for quantitative peptidomics. In this protocol, we describe the method in which peptides are reacted with formaldehyde and sodium cyanoborohydride, which converts primary and secondary amines into tertiary amines. By using different combinations of regular reagents, deuterated reagents (2H), and reagents containing deuterium and 13C, it is possible to produce five isotopically distinct forms of the methylated peptides, which can be quantified by mass spectrometry. Peptides with free N-termini that are primary amines incorporate two methyl groups using this procedure, which differ by 2 Da for each of the five isotopic combinations. Peptides that contain unmodified lysine residues incorporate additional pairs of methyl groups, leading to larger mass differences between isotopic forms. The reagents are commercially available, relatively inexpensive, and chemically stable.


Asunto(s)
Aminas , Péptidos , Péptidos/química , Espectrometría de Masas/métodos , Metilación , Proteómica/métodos
8.
Methods Mol Biol ; 2758: 89-108, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549010

RESUMEN

Peptidomics is the detection and identification of the peptides present in a sample, and quantitative peptidomics provides additional information about the amounts of these peptides. It is possible to perform absolute quantitation of peptide levels in which the biological sample is compared to synthetic standards of each peptide. More commonly, relative quantitation is performed to compare peptide levels between two or more samples. Relative quantitation can measure differences between all peptides that are detectable, which can exceed 1000 peptides in a complex sample. In this chapter, various techniques used for quantitative peptidomics are described along with discussion of the advantages and disadvantages of each approach. A guide to selecting the optimal quantitative approach is provided, based on the goals of the experiment and the resources that are available.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Espectrometría de Masas en Tándem/métodos , Proteómica/métodos , Péptidos , Estándares de Referencia
9.
Methods Mol Biol ; 2758: 213-225, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549016

RESUMEN

Peptidomic techniques are powerful tools to identify peptides in a biological sample. In the case of brain, which contains a complex mixture of cell types, standard peptidomics procedures reveal the major peptides in a dissected brain region. It is difficult to obtain information on peptides within a specific cell type using standard approaches, unless that cell type can be isolated. This protocol describes a targeted peptidomic approach that uses affinity chromatography to purify peptides that are substrates of carboxypeptidase E (CPE), an enzyme present in the secretory pathway of neuroendocrine cells. Many CPE products function as neuropeptides and/or peptide hormones, and therefore represent an important subset of the peptidome. Because CPE removes C-terminal Lys and Arg residues from peptide processing intermediates, organisms lacking CPE show a large decrease in the levels of the mature forms of most neuropeptides and peptide hormones, and a very large increase in the levels of the processing intermediates that contain C-terminal Lys and/or Arg (i.e., the CPE substrates). These CPE substrates can be purified on an anhydrotrypsin-agarose affinity resin, which specifically binds peptides with C-terminal basic residues. When this method is used with mice lacking CPE activity in genetically defined cell types, it allows the detection of peptides specifically produced in that cell type.


Asunto(s)
Neuropéptidos , Hormonas Peptídicas , Ratones , Animales , Carboxipeptidasa H/fisiología , Neuropéptidos/análisis , Cromatografía de Afinidad/métodos , Encéfalo/metabolismo , Hormonas Peptídicas/metabolismo , Carboxipeptidasas/metabolismo
10.
Methods Mol Biol ; 2758: 485-498, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549031

RESUMEN

The field of peptidomics has been under development since its start more than 20 years ago. In this chapter we provide a personal outlook for future directions in this field. The applications of peptidomics technologies are spreading more and more from classical research of peptide hormones and neuropeptides towards commercial applications in plant and food-science. Many clinical applications have been developed to analyze the complexity of biofluids, which are being addressed with new instrumentation, automization, and data processing. Additionally, the newly developed field of immunopeptidomics is showing promise for cancer therapies. In conclusion, peptidomics will continue delivering important information in classical fields like neuropeptides and peptide hormones, benefiting from improvements in state-of-the-art technologies. Moreover, new directions of research such as immunopeptidomics will further complement classical omics technologies and may become routine clinical procedures. Taken together, discoveries of new substances, networks, and applications of peptides can be expected in different disciplines.


Asunto(s)
Neuropéptidos , Hormonas Peptídicas , Proteómica/métodos , Neuropéptidos/química
11.
bioRxiv ; 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38328113

RESUMEN

Pulmonary arterial hypertension (PAH) is a rare and fatal vascular disease with heterogeneous clinical manifestations. To date, molecular determinants underlying the development of PAH and related outcomes remain poorly understood. Herein, we identify pulmonary primary oxysterol and bile acid synthesis (PPOBAS) as a previously unrecognized pathway central to PAH pathophysiology. Mass spectrometry analysis of 2,756 individuals across five independent studies revealed 51 distinct circulating metabolites that predicted PAH-related mortality and were enriched within the PPOBAS pathway. Across independent single-center PAH studies, PPOBAS pathway metabolites were also associated with multiple cardiopulmonary measures of PAH-specific pathophysiology. Furthermore, PPOBAS metabolites were found to be increased in human and rodent PAH lung tissue and specifically produced by pulmonary endothelial cells, consistent with pulmonary origin. Finally, a poly-metabolite risk score comprising 13 PPOBAS molecules was found to not only predict PAH-related mortality but also outperform current clinical risk scores. This work identifies PPOBAS as specifically altered within PAH and establishes needed prognostic biomarkers for guiding therapy in PAH.

12.
Sci Rep ; 13(1): 20408, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37990072

RESUMEN

Genomic resources are becoming available for Pisum but to link these to phenotypic diversity requires well marked populations segregating for relevant traits. Here we describe two such resources. Two recombinant inbred populations, derived from wide crosses in Pisum are described. One high resolution mapping population involves cv Caméor, for which the first pea whole genome assembly was obtained, crossed to JI0281, a basally divergent P. sativum sativum landrace from Ethiopia. The other is an inter sub-specific cross between P. s. sativum and the independently domesticated P. s. abyssinicum. The corresponding genetic maps provide information on chromosome level sequence assemblies and identify structural differences between the genomes of these two Pisum subspecies. In order to visualise chromosomal translocations that distinguish the mapping parents, we created a simplified version of Threadmapper to optimise it for interactive 3-dimensional display of multiple linkage groups. The genetic mapping of traits affecting seed coat roughness and colour, plant height, axil ring pigmentation, leaflet number and leaflet indentation enabled the definition of their corresponding genomic regions. The consequence of structural rearrangement for trait analysis is illustrated by leaf serration. These analyses pave the way for identification of the underlying genes and illustrate the utility of these publicly available resources. Segregating inbred populations derived from wide crosses in Pisum, together with the associated marker data, are made publicly available for trait dissection. Genetic analysis of these populations is informative about chromosome scale assemblies, structural diversity in the pea genome and has been useful for the fine mapping of several discrete and quantitative traits.


Asunto(s)
Pisum sativum , Sitios de Carácter Cuantitativo , Animales , Pisum sativum/genética , Mapeo Cromosómico/métodos , Fenotipo , Genómica , Animales de Laboratorio/genética , Ligamiento Genético , Cruzamientos Genéticos
13.
Tomography ; 9(5): 1949-1964, 2023 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-37888744

RESUMEN

Deep learning (DL) reconstruction techniques to improve MR image quality are becoming commercially available with the hope that they will be applicable to multiple imaging application sites and acquisition protocols. However, before clinical implementation, these methods must be validated for specific use cases. In this work, the quality of standard-of-care (SOC) T2w and a high-spatial-resolution (HR) imaging of the breast were assessed both with and without prototype DL reconstruction. Studies were performed using data collected from phantoms, 20 retrospectively collected SOC patient exams, and 56 prospectively acquired SOC and HR patient exams. Image quality was quantitatively assessed via signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and edge sharpness. Qualitatively, all in vivo images were scored by either two or four radiologist readers using 5-point Likert scales in the following categories: artifacts, perceived sharpness, perceived SNR, and overall quality. Differences in reader scores were tested for significance. Reader preference and perception of signal intensity changes were also assessed. Application of the DL resulted in higher average SNR (1.2-2.8 times), CNR (1.0-1.8 times), and image sharpness (1.2-1.7 times). Qualitatively, the SOC acquisition with DL resulted in significantly improved image quality scores in all categories compared to non-DL images. HR acquisition with DL significantly increased SNR, sharpness, and overall quality compared to both the non-DL SOC and the non-DL HR images. The acquisition time for the HR data only required a 20% increase compared to the SOC acquisition and readers typically preferred DL images over non-DL counterparts. Overall, the DL reconstruction demonstrated improved T2w image quality in clinical breast MRI.


Asunto(s)
Aprendizaje Profundo , Humanos , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Mama/diagnóstico por imagen , Relación Señal-Ruido
14.
Med ; 4(10): 668-686.e7, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37572659

RESUMEN

BACKGROUND: RH5 is a leading blood-stage candidate antigen for a Plasmodium falciparum vaccine; however, its safety and immunogenicity in malaria-endemic populations are unknown. METHODS: A phase 1b, single-center, dose-escalation, age-de-escalation, double-blind, randomized, controlled trial was conducted in Bagamoyo, Tanzania (NCT03435874). Between 12th April and 25th October 2018, 63 healthy adults (18-35 years), young children (1-6 years), and infants (6-11 months) received a priming dose of viral-vectored ChAd63 RH5 or rabies control vaccine. Sixty participants were boosted with modified vaccinia virus Ankara (MVA) RH5 or rabies control vaccine 8 weeks later and completed 6 months of follow-up post priming. Primary outcomes were the number of solicited and unsolicited adverse events post vaccination and the number of serious adverse events over the study period. Secondary outcomes included measures of the anti-RH5 immune response. FINDINGS: Vaccinations were well tolerated, with profiles comparable across groups. No serious adverse events were reported. Vaccination induced RH5-specific cellular and humoral responses. Higher anti-RH5 serum immunoglobulin G (IgG) responses were observed post boost in young children and infants compared to adults. Vaccine-induced antibodies showed growth inhibition activity (GIA) in vitro against P. falciparum blood-stage parasites; their highest levels were observed in infants. CONCLUSIONS: The ChAd63-MVA RH5 vaccine shows acceptable safety and reactogenicity and encouraging immunogenicity in children and infants residing in a malaria-endemic area. The levels of functional GIA observed in RH5-vaccinated infants are the highest reported to date following human vaccination. These data support onward clinical development of RH5-based blood-stage vaccines to protect against clinical malaria in young African infants. FUNDING: Medical Research Council, London, UK.


Asunto(s)
Vacunas contra la Malaria , Malaria Falciparum , Adulto , Niño , Preescolar , Humanos , Lactante , Adenovirus de los Simios , Anticuerpos Antivirales , Vacunas contra la Malaria/efectos adversos , Vacunas contra la Malaria/inmunología , Malaria Falciparum/prevención & control , Rabia , Tanzanía , Adolescente , Adulto Joven , Método Doble Ciego
15.
Pediatr Cardiol ; 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37566242

RESUMEN

We present the clinical course and echocardiographic and genetic findings of two fetuses with an unusual vascular ring, created by a left aortic arch with a right arterial duct and an aberrant right subclavian artery. One fetus was diagnosed with 22q11.2 microdeletion and the other became symptomatic in infancy. It is important to consider the position of the arterial ductal ligament in patients who present with tracheoesophageal compressive symptoms in the presence of a left aortic arch. These cases also highlight that a vascular ring formed from a left arch may have similar associations to a vascular ring formed by a right aortic arch.

16.
Sci Transl Med ; 15(704): eadf1782, 2023 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-37437014

RESUMEN

There are no licensed vaccines against Plasmodium vivax. We conducted two phase 1/2a clinical trials to assess two vaccines targeting P. vivax Duffy-binding protein region II (PvDBPII). Recombinant viral vaccines using chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) vectors as well as a protein and adjuvant formulation (PvDBPII/Matrix-M) were tested in both a standard and a delayed dosing regimen. Volunteers underwent controlled human malaria infection (CHMI) after their last vaccination, alongside unvaccinated controls. Efficacy was assessed by comparisons of parasite multiplication rates in the blood. PvDBPII/Matrix-M, given in a delayed dosing regimen, elicited the highest antibody responses and reduced the mean parasite multiplication rate after CHMI by 51% (n = 6) compared with unvaccinated controls (n = 13), whereas no other vaccine or regimen affected parasite growth. Both viral-vectored and protein vaccines were well tolerated and elicited expected, short-lived adverse events. Together, these results support further clinical evaluation of the PvDBPII/Matrix-M P. vivax vaccine.


Asunto(s)
Malaria , Parásitos , Humanos , Animales , Plasmodium vivax , Vacunación
17.
Vascul Pharmacol ; 151: 107181, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37164245

RESUMEN

Deficiency of iron­sulfur (FeS) clusters promotes metabolic rewiring of the endothelium and the development of pulmonary hypertension (PH) in vivo. Joining a growing number of FeS biogenesis proteins critical to pulmonary endothelial function, recent data highlighted that frataxin (FXN) reduction drives Fe-S-dependent genotoxic stress and senescence across multiple types of pulmonary vascular disease. Trinucleotide repeat mutations in the FXN gene cause Friedreich's ataxia, a disease characterized by cardiomyopathy and neurodegeneration. These tissue-specific phenotypes have historically been attributed to mitochondrial reprogramming and oxidative stress. Whether FXN coordinates both nuclear and mitochondrial processes in the endothelium is unknown. Here, we aim to identify the mitochondria-specific effects of FXN deficiency in the endothelium that predispose to pulmonary hypertension. Our data highlight an Fe-S-driven metabolic shift separate from previously described replication stress whereby FXN knockdown diminished mitochondrial respiration and increased glycolysis and oxidative species production. In turn, FXN-deficient endothelial cells had increased vasoconstrictor production (EDN1) and decreased nitric oxide synthase expression (NOS3). These data were observed in primary pulmonary endothelial cells after pharmacologic inhibition of FXN, mice carrying a genetic endothelial deletion of FXN, and inducible pluripotent stem cell-derived endothelial cells from patients with FXN mutations. Altogether, this study indicates FXN is an upstream driver of pathologic aberrations in metabolism and genomic stability. Moreover, our study highlights FXN-specific vasoconstriction in vivo, prompting future studies to investigate available and novel PH therapies in contexts of FXN deficiency.


Asunto(s)
Hipertensión Pulmonar , Ratones , Animales , Hipertensión Pulmonar/metabolismo , Células Endoteliales/metabolismo , Mitocondrias/metabolismo , Respiración , Frataxina
18.
Chem Sci ; 14(19): 5062-5068, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37206382

RESUMEN

Robust methods for the synthesis of mixed phosphotriesters are essential to accelerate the development of novel phosphate-containing bioactive molecules. To enable efficient cellular uptake, phosphate groups are commonly masked with biolabile protecting groups, such as S-acyl-2-thioethyl (SATE) esters, that are removed once the molecule is inside the cell. Typically, bis-SATE-protected phosphates are synthesised through phosphoramidite chemistry. This approach, however, suffers from issues with hazardous reagents and can give unreliable yields, especially when applied to the synthesis of sugar-1-phosphate derivatives as tools for metabolic oligosaccharide engineering. Here, we report the development of an alternative approach that gives access to bis-SATE phosphotriesters in two steps from an easy to synthesise tri(2-bromoethyl)phosphotriester precursor. We demonstrate the viability of this strategy using glucose as a model substrate, onto which a bis-SATE-protected phosphate is introduced either at the anomeric position or at C6. We show compability with various protecting groups and further explore the scope and limitations of the methodology on different substrates, including N-acetylhexosamine and amino acid derivatives. The new approach facilitates the synthesis of bis-SATE-protected phosphoprobes and prodrugs and provides a platform that can boost further studies aimed at exploring the unique potential of sugar phosphates as research tools.

19.
Tomography ; 9(3): 967-980, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37218939

RESUMEN

Graphically prescribed patient-specific imaging volumes and local pre-scan volumes are routinely placed by MRI technologists to optimize image quality. However, manual placement of these volumes by MR technologists is time-consuming, tedious, and subject to intra- and inter-operator variability. Resolving these bottlenecks is critical with the rise in abbreviated breast MRI exams for screening purposes. This work proposes an automated approach for the placement of scan and pre-scan volumes for breast MRI. Anatomic 3-plane scout image series and associated scan volumes were retrospectively collected from 333 clinical breast exams acquired on 10 individual MRI scanners. Bilateral pre-scan volumes were also generated and reviewed in consensus by three MR physicists. A deep convolutional neural network was trained to predict both the scan and pre-scan volumes from the 3-plane scout images. The agreement between the network-predicted volumes and the clinical scan volumes or physicist-placed pre-scan volumes was evaluated using the intersection over union, the absolute distance between volume centers, and the difference in volume sizes. The scan volume model achieved a median 3D intersection over union of 0.69. The median error in scan volume location was 2.7 cm and the median size error was 2%. The median 3D intersection over union for the pre-scan placement was 0.68 with no significant difference in mean value between the left and right pre-scan volumes. The median error in the pre-scan volume location was 1.3 cm and the median size error was -2%. The average estimated uncertainty in positioning or volume size for both models ranged from 0.2 to 3.4 cm. Overall, this work demonstrates the feasibility of an automated approach for the placement of scan and pre-scan volumes based on a neural network model.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Redes Neurales de la Computación , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Estudios Retrospectivos , Mama/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos
20.
Sci Rep ; 13(1): 5326, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-37005423

RESUMEN

We address the temporal organization of circadian and ultradian rhythms, crucial for understanding biological timekeeping in behavior, physiology, metabolism, and alignment with geophysical time. Using a newly developed five-steps wavelet-based approach to analyze high-resolution time series of metabolism in yeast cultures and spontaneous movement, metabolism, and feeding behavior in mice, rats, and quails, we describe a dynamically coherent pattern of rhythms spanning over a broad range of temporal scales (hours to minutes). The dynamic pattern found shares key features among the four, evolutionary distant, species analyzed. Specifically, a branching appearance given by splitting periods from 24 h into 12 h, 8 h and below in mammalian and avian species, or from 14 h down to 0.07 h in yeast. Scale-free fluctuations with long-range correlations prevail below ~ 4 h. Synthetic time series modeling support a scenario of coexisting behavioral rhythms, with circadian and ultradian rhythms at the center of the emergent pattern observed.


Asunto(s)
Saccharomyces cerevisiae , Ritmo Ultradiano , Ratas , Ratones , Animales , Codorniz , Conducta Alimentaria , Movimiento , Ritmo Circadiano , Mamíferos
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