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1.
Plant J ; 116(5): 1421-1440, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37646674

RESUMEN

Despite the identification of clubroot resistance genes in various Brassica crops our understanding of the genetic basis of immunity to Plasmodiophora brassicae infection in the model plant Arabidopsis thaliana remains limited. To address this issue, we performed a screen of 142 natural accessions and identified 11 clubroot-resistant Arabidopsis lines. Genome-wide association analysis identified several genetic loci significantly linked with resistance. Three genes from two of these loci were targeted for deletion by CRISPR/Cas9 mutation in resistant accessions Est-1 and Uod-1. Deletion of Resistance to Plasmodiophora brassicae 1 (RPB1) rendered both lines susceptible to the P. brassicae pathotype P1+. Further analysis of rpb1 knock-out Est-1 and Uod-1 lines showed that the RPB1 protein is required for activation of downstream defence responses, such as the expression of phytoalexin biosynthesis gene CYP71A13. RPB1 has recently been shown to encode a cation channel localised in the endoplasmic reticulum. The clubroot susceptible Arabidopsis accession Col-0 lacks a functional RPB1 gene; when Col-0 is transformed with RPB1 expression driven by its native promoter it is capable of activating RPB1 transcription in response to infection, but this is not sufficient to confer resistance. Transient expression of RPB1 in Nicotiana tabacum induced programmed cell death in leaves. We conclude that RPB1 is a critical component of the defence response to P. brassicae infection in Arabidopsis, acting downstream of pathogen recognition but required for the elaboration of effective resistance.


Asunto(s)
Arabidopsis , Brassica , Plasmodiophorida , Arabidopsis/metabolismo , Enfermedades de las Plantas , Estudio de Asociación del Genoma Completo , Brassica/genética
2.
New Phytol ; 243(6): 2075-2092, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39101283

RESUMEN

Evolutionary emergence of specialised vascular tissues has enabled plants to coordinate their growth and adjust to unfavourable external conditions. Whilst holding a pivotal role in long-distance transport, both xylem and phloem can be encroached on by various biotic factors for systemic invasion and hijacking of nutrients. Therefore, a complete understanding of the strategies deployed by plants against such pathogens to restrict their entry and establishment within plant tissues, is of key importance for the future development of disease-tolerant crops. In this review, we aim to describe how microorganisms exploit the plant vascular system as a route for gaining access and control of different host tissues and metabolic pathways. Highlighting several biological examples, we detail the wide range of host responses triggered to prevent or hinder vascular colonisation and effectively minimise damage upon biotic invasions.


Asunto(s)
Interacciones Huésped-Patógeno , Transporte Biológico , Xilema/fisiología , Xilema/metabolismo , Floema/metabolismo , Haz Vascular de Plantas/microbiología , Haz Vascular de Plantas/fisiología , Plantas/microbiología , Plantas/metabolismo , Enfermedades de las Plantas/microbiología
3.
J Sleep Res ; 2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37488062

RESUMEN

Certain neurophysiological characteristics of sleep, in particular slow oscillations (SOs), sleep spindles, and their temporal coupling, have been well characterised and associated with human memory abilities. Delta waves, which are somewhat higher in frequency and lower in amplitude compared to SOs, and their interaction with spindles have only recently been found to play a critical role in memory processing of rodents, through a competitive interaction between SO-spindle and delta-spindle coupling. However, human studies that comprehensively address delta wave interactions with spindles and SOs, as well as their functional role for memory are still lacking. Electroencephalographic data were acquired across three naps of 33 healthy older human participants (17 female) to investigate delta-spindle coupling and the interplay between delta- and SO-related activity. Additionally, we determined intra-individual stability of coupling measures and their potential link to the ability to form novel memories in a verbal memory task. Our results revealed weaker delta-spindle compared to SO-spindle coupling. Contrary to our initial hypothesis, we found no evidence for an opposing dependency between SO- and delta-related activities during non-rapid eye movement sleep. Moreover, the ratio between SO- and delta-nested spindles rather than SO-spindle and delta-spindle coupling measures by themselves predicted the ability to form novel memories best. In conclusion, our results do not confirm previous findings in rodents on competitive interactions between delta activity and SO-spindle coupling in older adults. However, they support the hypothesis that SO, delta wave, and spindle activity should be jointly considered when aiming to link sleep physiology and memory formation.

4.
Eur J Neurol ; 30(9): 2675-2683, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37159485

RESUMEN

BACKGROUND: Although the incidence of stroke in the young is rising, data on long-term outcomes in these patients are scarce. We thus aimed to investigate the long-term risk of recurrent vascular events and mortality in a multicenter study. METHODS: We followed 396 consecutive patients aged 18-55 years with ischemic stroke (IS) or transient ischemic attack (TIA) enrolled in three European centers during the period 2007-2010. A detailed outpatient clinical follow-up assessment was performed between 2018 and 2020. When an in-person follow-up visit was not possible, outcome events were assessed using electronic records and registry data. RESULTS: During a median follow-up of 11.8 (IQR 10.4-12.7) years, 89 (22.5%) patients experienced any recurrent vascular event, 62 (15.7%) had any cerebrovascular event, 34 (8.6%) had other vascular events, and 27 (6.8%) patients died. Cumulative 10-year incidence rate per 1000 person-years was 21.6 (95% CI 17.1-26.9) for any recurrent vascular event and 14.9 (95% CI 11.3-19.3) for any cerebrovascular event. The prevalence of cardiovascular risk factors increased over time, and 22 (13.5%) patients lacked any secondary preventive medication at the in-person follow-up. After adjustment for demographics and comorbidities, atrial fibrillation at baseline was found to be significantly associated with recurrent vascular events. CONCLUSIONS: This multicenter study shows a considerable risk of recurrent vascular events in young IS and TIA patients. Further studies should investigate whether detailed individual risk assessment, modern secondary preventive strategies, and better patient adherence may reduce recurrence risk.


Asunto(s)
Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Ataque Isquémico Transitorio/complicaciones , Ataque Isquémico Transitorio/epidemiología , Recurrencia Local de Neoplasia , Accidente Cerebrovascular/complicaciones , Medición de Riesgo , Incidencia , Accidente Cerebrovascular Isquémico/complicaciones , Factores de Riesgo , Recurrencia , Estudios de Seguimiento
5.
Neuromodulation ; 26(8): 1592-1601, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35981956

RESUMEN

BACKGROUND: Oscillatory rhythms during sleep, such as slow oscillations (SOs) and spindles and, most importantly, their coupling, are thought to underlie processes of memory consolidation. External slow oscillatory transcranial direct current stimulation (so-tDCS) with a frequency of 0.75 Hz has been shown to improve this coupling and memory consolidation; however, effects varied quite markedly between individuals, studies, and species. In this study, we aimed to determine how precisely the frequency of stimulation must match the naturally occurring SO frequency in individuals to best improve SO-spindle coupling. Moreover, we systematically tested stimulation durations necessary to induce changes. MATERIALS AND METHODS: We addressed these questions by comparing so-tDCS with individualized frequency to standardized frequency of 0.75 Hz in a within-subject design with 28 older participants during napping while stimulation train durations were systematically varied between 30 seconds, 2 minutes, and 5 minutes. RESULTS: Stimulation trains as short as 30 seconds were sufficient to modulate the coupling between SOs and spindle activity. Contrary to our expectations, so-tDCS with standardized frequency indicated stronger aftereffects regarding SO-spindle coupling than individualized frequency. Angle and variance of spindle maxima occurrence during the SO cycle were similarly modulated. CONCLUSIONS: In sum, short stimulation trains were sufficient to induce significant changes in sleep physiology, allowing for more trains of stimulation, which provides methodological advantages and possibly even larger behavioral effects in future studies. Regarding individualized stimulation frequency, further options of optimization need to be investigated, such as closed-loop stimulation, to calibrate stimulation frequency to the SO frequency at the time of stimulation onset. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT04714879.


Asunto(s)
Consolidación de la Memoria , Estimulación Transcraneal de Corriente Directa , Humanos , Sueño/fisiología , Consolidación de la Memoria/fisiología , Electroencefalografía
6.
Plant J ; 106(5): 1338-1355, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33738886

RESUMEN

Drought stress impacts the quality and yield of Pisum sativum. Here, we show how short periods of limited water availability during the vegetative stage of pea alters phloem sap content and how these changes are connected to strategies used by plants to cope with water deficit. We have investigated the metabolic content of phloem sap exudates and explored how this reflects P. sativum physiological and developmental responses to drought. Our data show that drought is accompanied by phloem-mediated redirection of the components that are necessary for cellular respiration and the proper maintenance of carbon/nitrogen balance during stress. The metabolic content of phloem sap reveals a shift from anabolic to catabolic processes as well as the developmental plasticity of P. sativum plants subjected to drought. Our study underlines the importance of phloem-mediated transport for plant adaptation to unfavourable environmental conditions. We also show that phloem exudate analysis can be used as a useful proxy to study stress responses in plants. We propose that the decrease in oleic acid content within phloem sap could be considered as a potential marker of early signalling events mediating drought response.


Asunto(s)
Carbono/metabolismo , Nitrógeno/metabolismo , Pisum sativum/fisiología , Adaptación Fisiológica , Transporte Biológico , Sequías , Genotipo , Ácido Oléico/metabolismo , Pisum sativum/anatomía & histología , Pisum sativum/genética , Floema/anatomía & histología , Floema/genética , Floema/fisiología , Exudados de Plantas , Hojas de la Planta/anatomía & histología , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Estrés Fisiológico , Agua/fisiología
7.
Plant Cell ; 30(12): 3058-3073, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30413655

RESUMEN

Successful biotrophic plant pathogens can divert host nutrition toward infection sites. Here we describe how the protist Plasmodiophora brassicae establishes a long-term feeding relationship with its host by stimulating phloem differentiation and phloem-specific expression of sugar transporters within developing galls. Development of galls in infected Arabidopsis (Arabidopsis thaliana) plants is accompanied by stimulation of host BREVIS RADIX, COTYLEDON VASCULAR PATTERN, and OCTOPUS gene expression leading to an increase in phloem complexity. We characterized how the arrest of this developmental reprogramming influences both the host and the invading pathogen. Furthermore, we found that infection leads to phloem-specific accumulation of SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTERS11 and 12 facilitating local distribution of sugars toward the pathogen. Utilizing Fourier-transform infrared microspectroscopy to monitor spatial distribution of carbohydrates, we found that infection leads to the formation of a strong physiological sink at the site of infection. High resolution metabolic and structural imaging of sucrose distributions revealed that sweet11 sweet12 double mutants are impaired in sugar transport toward the pathogen, delaying disease progression. This work highlights the importance of precise regulation of sugar partitioning for plant-pathogen interactions and the dependence of P brassicae's performance on its capacity to induce a phloem sink at the feeding site.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Floema/citología , Floema/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Enfermedades de las Plantas , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier
8.
Chem Soc Rev ; 49(22): 7879-7892, 2020 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-32500897

RESUMEN

Droplets moving on solid surfaces are at the heart of many phenomena of fundamental and applied interest in chemistry, physics and materials science. On the fundamental side, as they are often subject to evaporation, these droplets are a beautiful and complex example of non-equilibrium physical chemistry, whose explanation and understanding still capture the imagination of multiple researchers around the world. In technology, droplets on solid surfaces are of widespread use for handling small amounts of matter, for harvesting energy, for manufacturing materials and for sensing chemical and biological analytes. A key underlying factor of their widespread applicability is the degree of control that can be achieved over their transport on surfaces. This tutorial review provides an overview of recent progress towards the programmable transport of droplets on solid surfaces. We will first present the physical principles behind the main experimental strategies for droplet transport. We will then review the most inspiring applications where these strategies have been employed in chemistry, materials science and engineering. Finally, we will outline possible future research directions for the programmable transport of droplets. Beyond projecting the reader at the forefront of this exciting field of physical chemistry, we believe that this tutorial review will inspire diverse, multidisciplinary scientific communities to devise novel ways of manipulating the flow of matter, energy and information on solid surfaces using programmable droplets as vessels.

9.
Plant J ; 97(4): 715-729, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30431210

RESUMEN

Plasmodiophora brassicae is a soil-borne biotroph whose life cycle involves reprogramming host developmental processes leading to the formation of galls on its underground parts. Formation of such structures involves modification of the host cell cycle leading initially to hyperplasia, increasing the number of cells to be invaded, followed by overgrowth of cells colonised by the pathogen. Here we show that P. brassicae infection stimulates formation of the E2Fa/RBR1 complex and upregulation of MYB3R1, MYB3R4 and A- and B-type cyclin expression. These factors were previously described as important regulators of the G2-M cell cycle checkpoint. As a consequence of this manipulation, a large population of host hypocotyl cells are delayed in cell cycle exit and maintained in the proliferative state. We also report that, during further maturation of galls, enlargement of host cells invaded by the pathogen involves endoreduplication leading to increased ploidy levels. This study characterises two aspects of the cell cycle reprogramming efforts of P. brassicae: systemic, related to the disturbance of host hypocotyl developmental programs by preventing cell cycle exit; and local, related to the stimulation of cell enlargement via increased endocycle activity.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/microbiología , Ciclo Celular/genética , Plasmodiophorida/patogenicidad , Proteínas de Arabidopsis/genética , Ciclo Celular/fisiología , División Celular/genética , División Celular/fisiología , Regulación de la Expresión Génica de las Plantas/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología
10.
Int J Mol Sci ; 21(16)2020 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-32781659

RESUMEN

Lolium multiflorum/Festuca arundinacea introgression forms have been proved several times to be good models to identify key components of grass metabolism involved in the mechanisms of tolerance to water deficit. Here, for the first time, a relationship between photosynthetic and antioxidant capacities with respect to drought tolerance of these forms was analyzed in detail. Two closely related L. multiflorum/F. arundinacea introgression forms distinct in their ability to re-grow after cessation of prolonged water deficit in the field were selected and subjected to short-term drought in pots to dissect precisely mechanisms of drought tolerance in this group of plants. The studies revealed that the form with higher drought tolerance was characterized by earlier and higher accumulation of abscisic acid, more stable cellular membranes, and more balanced reactive oxygen species metabolism associated with a higher capacity of the antioxidant system under drought conditions. On the other hand, both introgression forms revealed the same levels of stomatal conductance, CO2 assimilation, and consequently, intrinsic water use efficiency under drought and recovery conditions. However, simultaneous higher adjustment of the Calvin cycle to water deficit and reduced CO2 availability, with respect to the accumulation and activity of plastid fructose-1,6-bisphosphate aldolase, were clearly visible in the form with higher drought tolerance.


Asunto(s)
Adaptación Fisiológica , Antioxidantes/metabolismo , Sequías , Festuca/fisiología , Lolium/fisiología , Fotosíntesis , Agua , Festuca/genética , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Peroxidación de Lípido , Lolium/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estomas de Plantas/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Suelo/química , Superóxidos/metabolismo
11.
Mol Plant Microbe Interact ; 32(10): 1259-1266, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31210556

RESUMEN

When plants are infected by Plasmodiophora brassicae, their developmental programs are subjected to extensive changes and the resultant clubroot disease is associated with formation of large galls on underground tissue. The pathogen's need to build an efficient feeding site as the disease progresses drives these changes, ensuring successful production of resting spores. This developmental reprogramming is an outcome of interactions between the pathogen and the infected host. During disease progression, we can observe alteration of growth regulator dynamics, patterns of cell proliferation and differentiation, increased cell expansion, and eventual cell wall degradation as well as the redirection of nutrients toward the pathogen. Recently, detailed studies of anatomical changes occurring during infection and studies profiling transcriptional responses have come together to provide a clearer understanding of the sequence of events and processes underlying clubroot disease. Additionally, genome sequencing projects have revealed P. brassicae's potential for the production of signaling molecules and effectors as well as its requirements and capacities with respect to taking up host nutrients. Integration of these new findings together with physiological studies can significantly advance our understanding of how P. brassicae brings about reprogramming of host development. This article summarizes the current state of knowledge on cellular changes induced by P. brassicae infection and aims to explain their impact and importance for both the host and the pathogen.


Asunto(s)
Arabidopsis , Interacciones Huésped-Parásitos , Plasmodiophorida , Arabidopsis/crecimiento & desarrollo , Arabidopsis/parasitología , Interacciones Huésped-Parásitos/fisiología , Enfermedades de las Plantas/parasitología , Plasmodiophorida/fisiología
12.
BMC Genomics ; 17: 272, 2016 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-27036196

RESUMEN

BACKGROUND: The protist Plasmodiophora brassicae is a soil-borne pathogen of cruciferous species and the causal agent of clubroot disease of Brassicas including agriculturally important crops such as canola/rapeseed (Brassica napus). P. brassicae has remained an enigmatic plant pathogen and is a rare example of an obligate biotroph that resides entirely inside the host plant cell. The pathogen is the cause of severe yield losses and can render infested fields unsuitable for Brassica crop growth due to the persistence of resting spores in the soil for up to 20 years. RESULTS: To provide insight into the biology of the pathogen and its interaction with its primary host B. napus, we produced a draft genome of P. brassicae pathotypes 3 and 6 (Pb3 and Pb6) that differ in their host range. Pb3 is highly virulent on B. napus (but also infects other Brassica species) while Pb6 infects only vegetable Brassica crops. Both the Pb3 and Pb6 genomes are highly compact, each with a total size of 24.2 Mb, and contain less than 2 % repetitive DNA. Clustering of genome-wide single nucleotide polymorphisms (SNP) of Pb3, Pb6 and three additional re-sequenced pathotypes (Pb2, Pb5 and Pb8) shows a high degree of correlation of cluster grouping with host range. The Pb3 genome features significant reduction of intergenic space with multiple examples of overlapping untranslated regions (UTRs). Dependency on the host for essential nutrients is evident from the loss of genes for the biosynthesis of thiamine and some amino acids and the presence of a wide range of transport proteins, including some unique to P. brassicae. The annotated genes of Pb3 include those with a potential role in the regulation of the plant growth hormones cytokinin and auxin. The expression profile of Pb3 genes, including putative effectors, during infection and their potential role in manipulation of host defence is discussed. CONCLUSION: The P. brassicae genome sequence reveals a compact genome, a dependency of the pathogen on its host for some essential nutrients and a potential role in the regulation of host plant cytokinin and auxin. Genome annotation supported by RNA sequencing reveals significant reduction in intergenic space which, in addition to low repeat content, has likely contributed to the P. brassicae compact genome.


Asunto(s)
Brassica/parasitología , Genoma de Protozoos , Interacciones Huésped-Parásitos/genética , Plasmodiophorida/genética , Arabidopsis , Productos Agrícolas/parasitología , Citocininas/metabolismo , ADN Protozoario/genética , Especificidad del Huésped , Ácidos Indolacéticos/metabolismo , Enfermedades de las Plantas/parasitología , Análisis de Secuencia de ARN , Transcriptoma
13.
Plant J ; 71(2): 226-38, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22394393

RESUMEN

Plasmodiophora brassicae (clubroot) infection leads to reprogramming of host development resulting in the formation of characteristic galls. In this work we explored the cellular events that underly gall formation in Arabidopsis thaliana with the help of molecular markers of cell division (CYCB1:GUS) and meristematic activity (ANT:GUS). Our results show that gall development involved the amplification of existing meristematic activities within the vascular cambium (VC) and phloem parenchyma (PP) cells in the region of the hypocotyl. Additionally we found that the increase in VC activity and prolonged maintenance of cambial-derived cells in a meristematic state was crucial for gall formation; disruption of the VC activity significantly decreased the gall size. Gall formation also perturbed vascular development with a significant reduction in xylem and increase in PP in infected plants. This situation was reflected in a decrease in transcripts of key factors promoting xylogenesis (VND6, VND7 and MYB46) and an increase in those promoting phloem formation and function (APL, SUC2). Finally we show, using the cell cycle inhibitor ICK1/KRP1 and a cle41 mutant with altered regulation of cambial stem cell maintenance and differentiation, that a decrease in gall formation did not prevent pathogen development. This finding demonstrates that although gall formation is a typical symptom of the disease and influences numbers of spores produced, it is not required for completion of the pathogen life cycle. Together, these results provide an insight into the relationship of the cellular events that accompany Plasmodiophora infection and their role in disease progression.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Meristema/crecimiento & desarrollo , Tumores de Planta/parasitología , Plasmodiophorida/crecimiento & desarrollo , Animales , Arabidopsis/citología , Arabidopsis/genética , Arabidopsis/parasitología , Proteínas de Arabidopsis/metabolismo , Cámbium/citología , Cámbium/genética , Cámbium/crecimiento & desarrollo , Cámbium/parasitología , Diferenciación Celular , División Celular , Regulación de la Expresión Génica de las Plantas/genética , Interacciones Huésped-Patógeno , Hipocótilo/citología , Hipocótilo/genética , Hipocótilo/crecimiento & desarrollo , Hipocótilo/parasitología , Estadios del Ciclo de Vida , Meristema/citología , Meristema/genética , Meristema/parasitología , Modelos Biológicos , Mutación , Floema/citología , Floema/genética , Floema/crecimiento & desarrollo , Floema/parasitología , Raíces de Plantas/citología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/parasitología , Plasmodiophorida/patogenicidad , ARN de Planta/genética , Proteínas Recombinantes de Fusión , Virulencia , Xilema/citología , Xilema/genética , Xilema/crecimiento & desarrollo , Xilema/parasitología
14.
Med Sci Educ ; 33(6): 1319-1322, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38188396

RESUMEN

A virtual addiction medicine elective was developed using interactive multimedia modules, active learning strategies, and patient-based cases. Student had opportunities for professional networking and interacting with physicians and patients. The elective was successful in boosting Year-1 medical students' confidence to screen, manage, and treat patients with substance abuse disorder.

15.
Invest Ophthalmol Vis Sci ; 64(2): 22, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36811882

RESUMEN

Purpose: Keratoconus (KTCN) is the most common corneal ectasia, characterized by pathological cone formation. Here, to provide an insight into the remodeling of the corneal epithelium (CE) during the course of the disease, we evaluated topographic regions of the CE of adult and adolescent patients with KTCN. Methods: The CE samples from 17 adult and 6 adolescent patients with KTCN, and 5 control CE samples were obtained during the CXL and PRK procedures, respectively. Three topographic regions, central, middle, and peripheral, were separated toward RNA sequencing and MALDI-TOF/TOF Tandem Mass Spectrometry. Data from transcriptomic and proteomic investigations were consolidated with the morphological and clinical findings. Results: The critical elements of the wound healing process, epithelial-mesenchymal transition, cell-cell communications, and cell-extracellular matrix interactions were altered in the particular corneal topographic regions. Abnormalities in pathways of neutrophils degranulation, extracellular matrix processing, apical junctions, IL, and IFN signaling were revealed to cooperatively disorganize the epithelial healing. Deregulation of the epithelial healing, G2M checkpoints, apoptosis, and DNA repair pathways in the middle CE topographic region in KTCN explains the presence of morphological changes in the corresponding doughnut pattern (a thin cone center surrounded by a thickened annulus). Despite similar morphological characteristics of CE samples in adolescents and adults with KTCN, their transcriptomic features were different. Values of the posterior corneal elevation differentiated adults with KTCN from adolescents with KTCN and correlated with the expression of TCHP, SPATA13, CNOT3, WNK1, TGFB2, and KRT12 genes. Conclusions: Identified molecular, morphological, and clinical features indicate the effect of impaired wound healing on corneal remodeling in KTCN CE.


Asunto(s)
Epitelio Corneal , Queratocono , Humanos , Adulto , Adolescente , Epitelio Corneal/metabolismo , Queratocono/metabolismo , Proteómica , Córnea/metabolismo , Cicatrización de Heridas , Reactivos de Enlaces Cruzados , Factores de Transcripción
16.
Med Educ Online ; 28(1): 2181745, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36840962

RESUMEN

BACKGROUND: The Michigan State College of Human Medicine began as an experiment to teach medical students in community-based settings and to create a primary care workforce for the state. Decades later, CHM faced internal and external challenges that spurred creation of a new curriculum - the Share Discovery Curriculum - founded on learning by doing and other learning theories. METHODS: A curricular design group (CDG) developed guiding principles for reform. Based on this, pedagogies and structures were selected to achieve this vision and developed into a curricular structure. Components of the first-year curriculum were piloted with a group of students and faculty members. RESULTS: Six guiding principles were endorsed, grounded in learning theories such as Dewey's Learning by Doing. Based upon these, several key features of the new curriculum emerged: learning communities; one-on-one coaches for students; symptom-based presentations for content; simulation, authentic clinical tasks, flipped classrooms, and modified practice-based learning as primary teaching modalities; early, integrated clinical and scientific learning; milestones as course learning objectives; and a multidimensional, competency-based assessment system. DISCUSSION: The process and outcomes described here are intended as an exemplar for schools undertaking curricular change. Early stakeholder engagement, faculty development, sustainable administrative systems, and managing complexity are core to the success of such endeavors.


Asunto(s)
Educación de Pregrado en Medicina , Estudiantes de Medicina , Humanos , Curriculum , Aprendizaje , Educación de Pregrado en Medicina/métodos , Michigan
17.
Plant J ; 66(6): 941-52, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21418354

RESUMEN

A classical view is that leaf shape is the result of local promotion of growth linked to cell proliferation. However, an alternative hypothesis is that leaf form is the result of local repression of growth in an otherwise growing system. Here we show that leaf form can indeed be manipulated in a directed fashion by local repression of growth. We show that targeting expression of an inhibitor of a cyclin-dependent kinase (KRP1) to the sinus area of developing leaves of Arabidopsis leads to local growth repression and the formation of organs with extreme lobing, including generation of leaflet-like organs. Directing KRP1 expression to other regions of the leaf using an miRNA target sequence tagging approach also leads to predictable novel leaf forms, and repression of growth in the leaf margin blocks the outgrowth of lobes, leading to a smoother perimeter. In addition, we show that decreased growth around the perimeter and across the leaf abaxial surface leads to a change in 3D form, as predicted by mechanical models of leaf growth. Our analysis provides experimental evidence that local repression of growth influences leaf shape, suggesting that it could be part of the mechanism of morphogenesis in plants in the context of an otherwise growing system.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/metabolismo , Hojas de la Planta/anatomía & histología , Arabidopsis/anatomía & histología , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Aumento de la Célula , Clonación Molecular , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Células del Mesófilo/citología , MicroARNs/metabolismo , Morfogénesis , Fenotipo , Epidermis de la Planta/anatomía & histología , Hojas de la Planta/crecimiento & desarrollo , Plantas Modificadas Genéticamente/anatomía & histología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo
18.
Plant Physiol ; 156(4): 2196-206, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21632970

RESUMEN

Understanding the relationship of the size and shape of an organism to the size, shape, and number of its constituent cells is a basic problem in biology; however, numerous studies indicate that the relationship is complex and often nonintuitive. To investigate this problem, we used a system for the inducible expression of genes involved in the G1/S transition of the plant cell cycle and analyzed the outcome on leaf shape. By combining a careful developmental staging with a quantitative analysis of the temporal and spatial response of cell division pattern and leaf shape to these manipulations, we found that changes in cell division frequency occurred much later than the observed changes in leaf shape. These data indicate that altered cell division frequency cannot be causally involved in the observed change of shape. Rather, a shift to a smaller cell size as a result of the genetic manipulations performed correlated with the formation of a smoother leaf perimeter, i.e. appeared to be the primary cellular driver influencing form. These data are discussed in the context of the relationship of cell division, growth, and leaf size and shape.


Asunto(s)
Arabidopsis/citología , Arabidopsis/genética , Ciclo Celular/genética , Tamaño de la Célula , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/anatomía & histología , Hojas de la Planta/citología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , División Celular/genética , Epidermis de la Planta/citología , Epidermis de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Factores de Tiempo
19.
J Vis Exp ; (186)2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35993752

RESUMEN

Infection of Brassica crops by the soilborne protist Plasmodiophora brassicae leads to gall formation on the underground organs. The formation of galls requires cellular reprogramming and changes in the metabolism of the infected plant. This is necessary to establish a pathogen-oriented physiological sink toward which the host nutrients are redirected. For a complete understanding of this particular plant-pathogen interaction and the mechanisms by which host growth and development are subverted and repatterned, it is essential to track and observe the internal changes accompanying gall formation with cellular resolution. Methods combining fluorescent stains and fluorescent proteins are often employed to study anatomical and physiological responses in plants. Unfortunately, the large size of galls and their low transparency act as major hurdles in performing whole-mount observations under the microscope. Moreover, low transparency limits the employment of fluorescence microscopy to study clubroot disease progression and gall formation. This article presents an optimized method for fixing and clearing galls to facilitate epifluorescence and confocal microscopy for inspecting P. brassicae-infected galls. A tissue-clearing protocol for rapid optical clearing was used followed by vibratome sectioning to detect anatomical changes and localize gene expression with promoter fusions and reporter lines tagged with fluorescent proteins. This method will prove useful for studying cellular and physiological responses in other pathogen-triggered structures in plants, such as nematode-induced syncytia and root knots, as well as leaf galls and deformations caused by insects.


Asunto(s)
Arabidopsis , Plasmodiophorida , Arabidopsis/metabolismo , Expresión Génica , Microscopía Fluorescente , Enfermedades de las Plantas/genética , Plasmodiophorida/genética
20.
BMJ Open ; 12(6): e059943, 2022 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-35688585

RESUMEN

INTRODUCTION: With the worldwide increase of life expectancy leading to a higher proportion of older adults experiencing age-associated deterioration of cognitive abilities, the development of effective and widely accessible prevention and therapeutic measures has become a priority and challenge for modern medicine. Combined interventions of cognitive training and transcranial direct current stimulation (tDCS) have shown promising results for counteracting age-associated cognitive decline. However, access to clinical centres for repeated sessions is challenging, particularly in rural areas and for older adults with reduced mobility, and lack of clinical personnel and hospital space prevents extended interventions in larger cohorts. A home-based and remotely supervised application of tDCS would make the treatment more accessible for participants and relieve clinical resources. So far, studies assessing feasibility of combined interventions with a focus on cognition in a home-based setting are rare. With this study, we aim to provide evidence for the feasibility and the effects of a multisession home-based cognitive training in combination with tDCS on cognitive functions of healthy older adults. METHODS AND ANALYSIS: The TrainStim-Home trial is a monocentric, randomised, double-blind, placebo-controlled study. Thirty healthy participants, aged 60-80 years, will receive 2 weeks of combined cognitive training and anodal tDCS over left dorsolateral prefrontal cortex (target intervention), compared with cognitive training plus sham stimulation. The cognitive training will comprise a letter updating task, and the participants will be stimulated for 20 min with 1.5 mA. The intervention sessions will take place at the participants' home, and primary outcome will be the feasibility, operationalised by two-thirds successfully completed sessions per participant. Additionally, performance in the training task and an untrained task will be analysed. ETHICS AND DISSEMINATION: Ethical approval was granted by the ethics committee of the University Medicine Greifswald. Results will be available through publications in peer-reviewed journals and presentations at national and international conferences. TRIAL REGISTRATION NUMBER: NCT04817124.


Asunto(s)
Trastornos del Conocimiento , Estimulación Transcraneal de Corriente Directa , Anciano , Cognición , Método Doble Ciego , Estudios de Factibilidad , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estimulación Transcraneal de Corriente Directa/métodos
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