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1.
Mol Cells ; : 100068, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38759887

RESUMO

The coordinated movement of germ layer progenitor cells reaches its peak at the dorsal side, where the Bmp signaling gradient is low, and minimum at the ventral side, where the Bmp gradient is high. This dynamic cell movement is regulated by the interplay of various signaling pathways. The non-canonical Wnt signaling cascade serves as a pivotal regulator of convergent and extension cellular movement, facilitated by the activation of small GTPases such as Rho, Rab, and Rac. However, the underlying cause of limited cell movement at the ventral side remains elusive. To explore the functional role of a key regulator in constraining gastrulation cell movement at the ventral side, we investigated the Bmp4-direct target gene, sizzled, to assess its potential role in inhibiting non-canonical Wnt signaling. In our current study, we demonstrated that ectopic expression of sizzled led to gastrulation defects in a dose-dependent manner, without altering cell fate specification. Overexpression of sizzled resulted in decreased elongation of Activin-treated animal cap and Keller explants. Furthermore, our immunoprecipitation assay unveiled the physical interaction of Sizzled with non-canonical Wnt ligand proteins (Wnt5 and Wnt11). Additionally, the activation of small GTPases involved in Wnt signaling mediation (RhoA and Rac1) was diminished upon sizzled overexpression. In summary, our findings suggest that Bmp4 signaling negatively modulates cell movement from the ventral side of the embryo by inducing sizzled expression during early Xenopus gastrulation.

2.
Sci Rep ; 14(1): 8922, 2024 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637565

RESUMO

The Bmp/Smad1 pathway plays a crucial role in developmental processes and tissue homeostasis. Mitogen-activated protein kinase (Mapk)/Erk mediated phosphorylation of Smad1 in the linker region leads to Smad1 degradation, cytoplasmic retention and inhibition of Bmp/Smad1 signaling. While Fgf/Erk pathway has been documented to inhibit Bmp/Smad1 signaling, several studies also suggests the cooperative interaction between these two pathways in different context. However, the precise role and molecular pathway of this collaborative interaction remain obscure. Here, we identified Xbra induced by Fgf/Erk signaling as a factor in a protective mechanism for Smad1. Xbra physically interacted with the linker region phosphorylated Smad1 to make Xbra/Smad1/Smad4 trimeric complex, leading to Smad1 nuclear localization and protecting it from ubiquitin-mediated proteasomal degradation. This interaction of Xbra/Smad1/Smad4 led to sustained nuclear localization of Smad1 and the upregulation of lateral mesoderm genes, while concurrently suppression of neural and blood forming genes. Taken together, the results suggests Xbra-dependent cooperative interplays between Fgf/Erk and Bmp/Smad1 signaling during lateral mesoderm specification in Xenopus embryos.


Assuntos
Proteínas Quinases Ativadas por Mitógeno , Transdução de Sinais , Animais , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Sistema Nervoso/metabolismo , Fosforilação , Proteína Smad1/genética , Proteína Smad1/metabolismo , Xenopus laevis/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo
3.
Mol Cells ; 47(4): 100058, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38522664

RESUMO

A comprehensive regulatory network of transcription factors controls the dorsoventral patterning of the body axis in developing vertebrate embryos. Bone morphogenetic protein signaling is essential for activating the Ventx family of homeodomain transcription factors, which regulates embryonic patterning and germ layer identity during Xenopus gastrulation. Although Ventx1.1 and Ventx2.1 of the Xenopus Ventx family have been extensively investigated, Ventx3.2 remains largely understudied. Therefore, this study aimed to investigate the transcriptional regulation of ventx3.2 during the embryonic development of Xenopus. We used goosecoid (Gsc) genome-wide chromatin immunoprecipitation-sequencing data to isolate and replicate the promoter region of ventx3.2. Serial deletion and site-directed mutagenesis were used to identify the cis-acting elements for Gsc and caudal type homeobox 1 (Cdx1) within the ventx3.2 promoter. Cdx1 and Gsc differentially regulated ventx3.2 transcription in this study. Additionally, positive cis-acting and negative response elements were observed for Cdx1 and Gsc, respectively, within the 5' flanking region of the ventx3.2 promoter. This result was corroborated by mapping the active Cdx1 response element (CRE) and Gsc response element (GRE). Moreover, a point mutation within the CRE and GRE completely abolished the activator and repressive activities of Cdx1 and Gsc, respectively. Furthermore, the chromatin immunoprecipitation-polymerase chain reaction confirmed the direct binding of Cdx1 and Gsc to the CRE and GRE, respectively. Inhibition of Cdx1 and Gsc activities at their respective functional regions, namely, the ventral marginal zone and dorsal marginal zone, reversed their effects on ventx3.2 transcription. These results indicate that Cdx1 and Gsc modulate ventx3.2 transcription in the ventral marginal zone and dorsal marginal zone by directly binding to the promoter region during Xenopus gastrulation.


Assuntos
Gástrula , Proteínas de Homeodomínio , Regiões Promotoras Genéticas , Proteínas de Xenopus , Animais , Regiões Promotoras Genéticas/genética , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Gástrula/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 4/genética , Xenopus laevis/genética , Xenopus laevis/metabolismo , Ligação Proteica , Transcrição Gênica , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteína Goosecoid/genética , Proteína Goosecoid/metabolismo
4.
J Clin Med ; 12(16)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37629389

RESUMO

Background: Some patients with mild cognitive impairment (MCI) experience gait disturbances. However, there are few reports on the relationship between gait disturbance and cognitive function in patients with MCI. Therefore, we investigated the neural correlates of gait characteristics related to cognitive dysfunction. Methods: Eighty patients diagnosed with MCI from three dementia centers in Gangwon-do, Korea, were recruited for this study. We defined MCI as a Clinical Dementia Rating global score of 0.5 or higher, with a memory domain score of 0.5 or greater. The patients were classified as having either higher or lower MMSE and the groups were based on their Mini Mental Status Examination z-scores. Multiple logistic regression analysis was performed to examine the association between the gait characteristics and cognitive impairment. Analyses included variables such as age, sex, years of education, number of comorbidities, body mass index, and height. Results: Gait velocity, step count, step length, heel-to-heel base support, swing and stance phase duration, and support time were associated with cognitive function. A decrease in gray matter volume in the right pericalcarine area was associated with gait characteristics related to cognitive dysfunction. An increase in the curvature of gray matter in the right entorhinal, right lateral orbitofrontal, right cuneus, and right and left pars opercularis areas was also associated with gait characteristics related to cognitive dysfunction. Conclusion: Since gait impairment is an important factor in determining activities of daily living in patients with mild cognitive impairment, the evaluation of gait and cognitive functions in patients with mild cognitive impairment is important.

5.
Int J Mol Sci ; 24(8)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37108717

RESUMO

Fibroblast growth factors (FGFs) encode a large family of growth factor proteins that activate several intracellular signaling pathways to control diverse physiological functions. The human genome encodes 22 FGFs that share a high sequence and structural homology with those of other vertebrates. FGFs orchestrate diverse biological functions by regulating cellular differentiation, proliferation, and migration. Dysregulated FGF signaling may contribute to several pathological conditions, including cancer. Notably, FGFs exhibit wide functional diversity among different vertebrates spatiotemporally. A comparative study of FGF receptor ligands and their diverse roles in vertebrates ranging from embryonic development to pathological conditions may expand our understanding of FGF. Moreover, targeting diverse FGF signals requires knowledge regarding their structural and functional heterogeneity among vertebrates. This study summarizes the current understanding of human FGF signals and correlates them with those in mouse and Xenopus models, thereby facilitating the identification of therapeutic targets for various human disorders.


Assuntos
Fatores de Crescimento de Fibroblastos , Neoplasias , Humanos , Animais , Camundongos , Xenopus laevis/metabolismo , Ligantes , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/genética , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Desenvolvimento Embrionário/genética , Neoplasias/genética
6.
Front Endocrinol (Lausanne) ; 14: 1124419, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875474

RESUMO

Cellular aging is the most severe risk factor for neurodegenerative disease. Simultaneously, oxidative stress (OS) is a critical factor in the aging process, resulting from an imbalance between reactive oxygen and nitrogen species and the antioxidant defense system. Emerging evidence indicates that OS is a common cause of several age-related brain pathologies, including cerebrovascular diseases. Elevated OS disrupts endothelial functional ability by diminishing the bioavailability of nitric oxide (a vascular dilator), induces atherosclerosis, and impairs vasculature, which are all common characteristics of cerebrovascular disease. In this review, we summarize evidence supporting an active role of OS in cerebrovascular disease progression, focusing primarily on stroke pathogenesis. We briefly discuss hypertension, diabetes, heart disease, and genetic factors that are often linked to OS and are considered associated factors influencing stroke pathology. Finally, we discuss the current pharmaceutics/therapeutics available for treating several cerebrovascular diseases.


Assuntos
Transtornos Cerebrovasculares , Hipertensão , Doenças Neurodegenerativas , Acidente Vascular Cerebral , Humanos , Estresse Oxidativo
7.
Cells ; 12(6)2023 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-36980215

RESUMO

The reciprocal inhibition between two signaling centers, the Spemann organizer (dorsal mesoderm) and ventral region (mesoderm and ectoderm), collectively regulate the overall development of vertebrate embryos. Each center expresses key homeobox transcription factors (TFs) that directly control target gene transcription. Goosecoid (Gsc) is an organizer (dorsal mesoderm)-specific TF known to induce dorsal fate and inhibit ventral/ectodermal specification. Ventx1.1 (downstream of Bmp signaling) induces the epidermal lineage and inhibits dorsal organizer-specific genes from the ventral region. Chordin (Chrd) is an organizer-specific secreted Bmp antagonist whose expression is primarily activated by Gsc. Alternatively, chrd expression is repressed by Bmp/Ventx1.1 in the ventral/epidermal region. However, the regulatory mechanisms underlying the transcription mediated by Gsc and Ventx1.1 remain elusive. Here, we found that the chrd promoter contained two cis-acting response elements that responded negatively to Ventx1.1 and positively to Gsc. In the ventral/ectodermal region, Ventx1.1 was directly bound to the Ventx1.1 response element (VRE) and inhibited chrd transcription. In the organizer region, Gsc was bound to the Gsc response elements (GRE) to activate chrd transcription. The Gsc-mediated positive response on the chrd promoter completely depended on another adjacent Wnt response cis-acting element (WRE), which was the TCF7 (also known as Tcf1) binding element. Site-directed mutagenesis of VRE, GRE, or WRE completely abolished the repressive or activator activity of Ventx1.1 and Gsc, respectively. The ChIP-PCR results confirmed the direct binding of Ventx1.1 and Gsc/Tcf7 to VRE and GRE/WRE, respectively. These results demonstrated that chrd expression is oppositely modulated by homeobox TFs, Ventx1.1, and Gsc/Tcf7 during the embryonic patterning of Xenopus gastrula.


Assuntos
Gástrula , Glicoproteínas , Proteína Goosecoid , Fatores de Transcrição , Proteínas de Xenopus , Xenopus laevis , Animais , Gástrula/metabolismo , Genes Homeobox , Proteína Goosecoid/genética , Proteína Goosecoid/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Glicoproteínas/metabolismo
8.
Int J Mol Sci ; 23(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36362118

RESUMO

Sizzled (Szl) is a secreted frizzled protein, having a sequence homology with the extracellular cysteine-rich domain (CRD) of the Wnt receptor, 'Frizzled'. Contrary to the other secreted frizzled like proteins (Sfrps), szl belongs to the bone morphogenetic protein 4 (Bmp4) synexpression group and is tightly coexpressed with Bmp4. What is not known is how the szl transcription achieves its Bmp4 synexpression pattern. To address the molecular details of szl transcription control, we cloned a promoter of size 1566 base pairs for szl (bps) from the Xenopus laevis genomic DNA. Luciferase and eGFP reporter gene results of this szl promoter (-1566 bp) in its activation and repression patterns by Bmp4/Smad1 and a dominant negative Bmp4 receptor (DNBR) were similar to those of the endogenous szl expression. Reporter gene assays and site-directed mutagenesis of the szl promoter mapped an active Bmp4/Smad1 response element (BRE) and a cis-acting element, which competitively share a direct binding site for Ventx1.1 and Ventx2.1 (a Ventx response element, VRE). Smad1 and ventx2.1 alone increased szl promoter activity; in addition, the binding of each protein component was enhanced with their coexpression. Interestingly, Ventx1.1 repressed this reporter gene activity; however, Ventx1.1 and Ventx2.1 together positively regulated the szl promoter activity. From our analysis, Ventx2.1 binding was enhanced by Ventx1.1, but Ventx1.1 inhibitory binding was inhibited by co-injection of Ventx2.1 for the VRE site. The inhibitory Ventx1.1 co-injection decreased Smad1 binding on the szl promoter. In a triple combination of overexpressed Smad1/Ventx1.1/Ventx2.1, the reduced binding of Smad1 from Ventx1.1 was recovered to that of the Smad1/Ventx2 combination. Collectively, this study provides evidence of Bmp4/Smad1 signaling for a primary immediate early response and its two oppositely behaving target transcription factors, Ventx1.1 and Ventx2.1, for a secondary response, as they together upregulate the szl promoter's activity to achieve szl expression in a Bmp4 synexpression manner.


Assuntos
Fatores de Transcrição , Proteínas de Xenopus , Animais , Xenopus laevis/genética , Xenopus laevis/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Fatores de Transcrição/metabolismo , Regiões Promotoras Genéticas , Sítios de Ligação , Proteína Morfogenética Óssea 4/genética , Proteína Morfogenética Óssea 4/metabolismo , Proteína Smad1/genética , Proteína Smad1/metabolismo
9.
PLoS One ; 16(12): e0259051, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34941878

RESUMO

BACKGROUND: Several studies have reported changes in the corpus callosum (CC) in Alzheimer's disease. However, the involved region differed according to the study population and study group. Using deep learning technology, we ensured accurate analysis of the CC in Alzheimer's disease. METHODS: We used the Open Access Series of Imaging Studies (OASIS) dataset to investigate changes in the CC. The individuals were divided into three groups using the Clinical Dementia Rating (CDR); 94 normal controls (NC) were not demented (NC group, CDR = 0), 56 individuals had very mild dementia (VMD group, CDR = 0.5), and 17 individuals were defined as having mild and moderate dementia (MD group, CDR = 1 or 2). Deep learning technology using a convolutional neural network organized in a U-net architecture was used to segment the CC in the midsagittal plane. Total CC length and regional magnetic resonance imaging (MRI) measurements of the CC were made. RESULTS: The total CC length was negatively associated with cognitive function. (beta = -0.139, p = 0.022) Among MRI measurements of the CC, the height of the anterior third (beta = 0.038, p <0.0001) and width of the body (beta = 0.077, p = 0.001) and the height (beta = 0.065, p = 0.001) and area of the splenium (beta = 0.059, p = 0.027) were associated with cognitive function. To distinguish MD from NC and VMD, the receiver operating characteristic analyses of these MRI measurements showed areas under the curves of 0.65-0.74. (total CC length = 0.705, height of the anterior third = 0.735, width of the body = 0.714, height of the splenium = 0.703, area of the splenium = 0.649). CONCLUSIONS: Among MRI measurements, total CC length, the height of the anterior third and width of the body, and the height and area of the splenium were associated with cognitive decline. They had fair diagnostic validity in distinguishing MD from NC and VMD.


Assuntos
Doença de Alzheimer/patologia , Atrofia/patologia , Disfunção Cognitiva/patologia , Corpo Caloso/patologia , Aprendizado Profundo , Adolescente , Adulto , Idoso , Atrofia/etiologia , Estudos de Casos e Controles , Criança , Disfunção Cognitiva/etiologia , Estudos Transversais , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medição de Risco , Adulto Jovem
10.
J Dev Biol ; 9(4)2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34842722

RESUMO

Germ layer specification and axis formation are crucial events in embryonic development. The Spemann organizer regulates the early developmental processes by multiple regulatory mechanisms. This review focuses on the responsive signaling in organizer formation and how the organizer orchestrates the germ layer specification in vertebrates. Accumulated evidence indicates that the organizer influences embryonic development by dual signaling. Two parallel processes, the migration of the organizer's cells, followed by the transcriptional activation/deactivation of target genes, and the diffusion of secreting molecules, collectively direct the early development. Finally, we take an in-depth look at active signaling that originates from the organizer and involves germ layer specification and patterning.

11.
Mol Cells ; 44(10): 723-735, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34711690

RESUMO

Spemann organizer is a center of dorsal mesoderm and itself retains the mesoderm character, but it has a stimulatory role for neighboring ectoderm cells in becoming neuroectoderm in gastrula embryos. Goosecoid (Gsc) overexpression in ventral region promotes secondary axis formation including neural tissues, but the role of gsc in neural specification could be indirect. We examined the neural inhibitory and stimulatory roles of gsc in the same cell and neighboring cells contexts. In the animal cap explant system, Gsc overexpression inhibited expression of neural specific genes including foxd4l1.1, zic3, ncam, and neurod. Genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) and promoter analysis of early neural genes of foxd4l1.1 and zic3 were performed to show that the neural inhibitory mode of gsc was direct. Site-directed mutagenesis and serially deleted construct studies of foxd4l1.1 promoter revealed that Gsc directly binds within the foxd4l1.1 promoter to repress its expression. Conjugation assay of animal cap explants was also performed to demonstrate an indirect neural stimulatory role for gsc. The genes for secretory molecules, Chordin and Noggin, were up-regulated in gsc injected cells with the neural fate only achieved in gsc uninjected neighboring cells. These experiments suggested that gsc regulates neuroectoderm formation negatively when expressed in the same cell and positively in neighboring cells via soluble factors. One is a direct suppressive circuit of neural genes in gsc expressing mesoderm cells and the other is an indirect stimulatory circuit for neurogenesis in neighboring ectoderm cells via secreted BMP antagonizers.


Assuntos
Proteína Goosecoid/metabolismo , Placa Neural/embriologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Animais
12.
Cells ; 10(10)2021 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-34685759

RESUMO

Inhibition of the bone morphogenetic proteins (BMPs) is the primary step toward neuroectoderm formation in vertebrates. In this process, the Spemann organizer of the dorsal mesoderm plays a decisive role by secreting several extracellular BMP inhibitors such as Chordin (Chrd). Chrd physically interacts with BMP proteins and inhibits BMP signaling, which triggers the expression of neural-specific transcription factors (TFs), including Foxd4l1.1. Thus, Chrd induces in a BMP-inhibited manner and promotes neuroectoderm formation. However, the regulatory feedback mechanism of Foxd4l1.1 on mesodermal genes expression during germ-layer specification has not been fully elucidated. In this study, we investigated the regulatory mechanism of Foxd4l1.1 on chrd (a mesodermal gene). We demonstrate that Foxd4l1.1 inhibits chrd expression during neuroectoderm formation in two ways: First, Foxd4l1.1 directly binds to FRE (Foxd4l1.1 response elements) within the chrd promoter region to inhibit transcription. Second, Foxd4l1.1 physically interacts with Smad2 and Smad3, and this interaction blocks Smad2 and Smad3 binding to activin response elements (AREs) within the chrd promoter. Site-directed mutagenesis of FRE within the chrd(-2250) promoter completely abolished repressor activity of the Foxd4l1.1. RT-PCR and reporter gene assay results indicate that Foxd4l1.1 strongly inhibits mesoderm- and ectoderm-specific marker genes to maintain neural fate. Altogether, these results suggest that Foxd4l1.1 negatively regulates chrd transcription by dual mechanism. Thus, our study demonstrates the existence of precise reciprocal regulation of chrd transcription during neuroectoderm and mesoderm germ-layer specification in Xenopus embryos.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Gástrula/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Transcrição Gênica , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/genética , Ativinas/metabolismo , Animais , Proteínas de Ligação a DNA/química , Ectoderma/metabolismo , Embrião não Mamífero/metabolismo , Genes Reporter , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mesoderma/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Domínios Proteicos , Elementos de Resposta/genética , Proteínas Smad/metabolismo , Proteínas de Xenopus/química
13.
Sensors (Basel) ; 21(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34372476

RESUMO

The Clock Drawing Test (CDT) is a rapid, inexpensive, and popular screening tool for cognitive functions. In spite of its qualitative capabilities in diagnosis of neurological diseases, the assessment of the CDT has depended on quantitative methods as well as manual paper based methods. Furthermore, due to the impact of the advancement of mobile smart devices imbedding several sensors and deep learning algorithms, the necessity of a standardized, qualitative, and automatic scoring system for CDT has been increased. This study presents a mobile phone application, mCDT, for the CDT and suggests a novel, automatic and qualitative scoring method using mobile sensor data and deep learning algorithms: CNN, a convolutional network, U-Net, a convolutional network for biomedical image segmentation, and the MNIST (Modified National Institute of Standards and Technology) database. To obtain DeepC, a trained model for segmenting a contour image from a hand drawn clock image, U-Net was trained with 159 CDT hand-drawn images at 128 × 128 resolution, obtained via mCDT. To construct DeepH, a trained model for segmenting the hands in a clock image, U-Net was trained with the same 159 CDT 128 × 128 resolution images. For obtaining DeepN, a trained model for classifying the digit images from a hand drawn clock image, CNN was trained with the MNIST database. Using DeepC, DeepH and DeepN with the sensor data, parameters of contour (0-3 points), numbers (0-4 points), hands (0-5 points), and the center (0-1 points) were scored for a total of 13 points. From 219 subjects, performance testing was completed with images and sensor data obtained via mCDT. For an objective performance analysis, all the images were scored and crosschecked by two clinical experts in CDT scaling. Performance test analysis derived a sensitivity, specificity, accuracy and precision for the contour parameter of 89.33, 92.68, 89.95 and 98.15%, for the hands parameter of 80.21, 95.93, 89.04 and 93.90%, for the numbers parameter of 83.87, 95.31, 87.21 and 97.74%, and for the center parameter of 98.42, 86.21, 96.80 and 97.91%, respectively. From these results, the mCDT application and its scoring system provide utility in differentiating dementia disease subtypes, being valuable in clinical practice and for studies in the field.


Assuntos
Cognição , Programas de Rastreamento , Algoritmos , Humanos , Testes Neuropsicológicos , Projetos de Pesquisa
14.
Cells ; 10(8)2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34440915

RESUMO

Fibroblast growth factors (FGFs) comprise a large family of growth factors, regulating diverse biological processes including cell proliferation, migration, and differentiation. Each FGF binds to a set of FGF receptors to initiate certain intracellular signaling molecules. Accumulated evidence suggests that in early development and adult state of vertebrates, FGFs also play exclusive and context dependent roles. Although FGFs have been the focus of research for therapeutic approaches in cancer, cardiovascular disease, and metabolic syndrome, in this review, we mainly focused on their role in germ layer specification and axis patterning during early vertebrate embryogenesis. We discussed the functional roles of FGFs and their interacting partners as part of the gene regulatory network for germ layer specification, dorsal-ventral (DV), and anterior-posterior (AP) patterning. Finally, we briefly reviewed the regulatory molecules and pharmacological agents discovered that may allow modulation of FGF signaling in research.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Camadas Germinativas/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , Vertebrados/metabolismo , Animais , Fatores de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/embriologia , Humanos , Modelos Biológicos , Ligação Proteica , Receptores de Fatores de Crescimento de Fibroblastos/genética , Vertebrados/embriologia , Vertebrados/genética
15.
Biochem Biophys Res Commun ; 559: 168-175, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-33945994

RESUMO

Transforming growth factor (TGF)ß/activin superfamily regulates diverse biological processes including germ layer specification and axis patterning in vertebrates. TGFß/activin leads to phosphorylation of Smad2 and Smad3, followed by regulation of their target genes. Activin treatment also induces the essential organizer gene chordin (chrd). The involvement of Smad2/3 in chrd expression has been unclear as to whether Smad2/3 involvement is direct or indirect and whether any cis-acting response elements for Smad2/3 are present in the proximal or distal regions of its promoter. In the present study, we isolated the -2250 bps portion of the chrd promoter, showing that it contained Smad2/3 direct binding sites at its distal portion, separate from the proximal locations of other organizer genes, goosecoid and cerberus. The pattern of transcription activation for the promoter (-2250 bps) was indistinguishable from that of the endogenous chrd in gastrula Xenopus embryos. Reporter gene assays and site-directed mutagenesis analysis of the chrd promoter mapped two active activin/Smad response elements (ARE1 and ARE2) for Smad2 and Smad3. For a differential chrd induction, Smad2 acted on both ARE1 and ARE2, but Smad3 was only active for ARE2. Collectively, the results demonstrate that the distal region of chrd promoter contains the direct binding cis-acting elements for Smad2 and Smad3, which differentially modulate chrd transcription in gastrula Xenopus embryos.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Animais , Gástrula/embriologia , Gástrula/metabolismo , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Smad2/genética , Proteína Smad3/genética , Ativação Transcricional , Proteínas de Xenopus/genética , Xenopus laevis/genética , Xenopus laevis/metabolismo
16.
Cells ; 11(1)2021 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-35011606

RESUMO

Gastrulation is a critical step in the establishment of a basic body plan during development. Convergence and extension (CE) cell movements organize germ layers during gastrulation. Noncanonical Wnt signaling has been known as major signaling that regulates CE cell movement by activating Rho and Rac. In addition, Bmp molecules are expressed in the ventral side of a developing embryo, and the ventral mesoderm region undergoes minimal CE cell movement while the dorsal mesoderm undergoes dynamic cell movements. This suggests that Bmp signal gradient may affect CE cell movement. To investigate whether Bmp signaling negatively regulates CE cell movements, we performed microarray-based screening and found that the transcription of Xenopus Arhgef3.2 (Rho guanine nucleotide exchange factor) was negatively regulated by Bmp signaling. We also showed that overexpression or knockdown of Xarhgef3.2 caused gastrulation defects. Interestingly, Xarhgef3.2 controlled gastrulation cell movements through interacting with Disheveled (Dsh2) and Dsh2-associated activator of morphogenesis 1 (Daam1). Our results suggest that Bmp gradient affects gastrulation cell movement (CE) via negative regulation of Xarhgef3.2 expression.


Assuntos
Movimento Celular , Embrião não Mamífero/citologia , Gastrulação , Transdução de Sinais , Xenopus laevis/embriologia , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Movimento Celular/genética , Polaridade Celular/genética , Gastrulação/genética , Técnicas de Silenciamento de Genes , Modelos Biológicos , Ligação Proteica/genética , Transcrição Gênica , Via de Sinalização Wnt/genética , Proteínas de Xenopus/química , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/genética , Proteína rhoA de Ligação ao GTP/metabolismo
17.
Sci Rep ; 10(1): 16780, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033315

RESUMO

Neuroectoderm formation is the first step in development of a proper nervous system for vertebrates. The developmental decision to form a non-neural ectoderm versus a neural one involves the regulation of BMP signaling, first reported many decades ago. However, the precise regulatory mechanism by which this is accomplished has not been fully elucidated, particularly for transcriptional regulation of certain key transcription factors. BMP4 inhibition is a required step in eliciting neuroectoderm from ectoderm and Foxd4l1.1 is one of the earliest neural genes highly expressed in the neuroectoderm and conserved across vertebrates, including humans. In this work, we focused on how Foxd4l1.1 downregulates the neural repressive pathway. Foxd4l1.1 inhibited BMP4/Smad1 signaling and triggered neuroectoderm formation in animal cap explants of Xenopus embryos. Foxd4l1.1 directly bound within the promoter of endogenous neural repressor ventx1.1 and inhibited ventx1.1 transcription. Foxd4l1.1 also physically interacted with Xbra in the nucleus and inhibited Xbra-induced ventx1.1 transcription. In addition, Foxd4l1.1 also reduced nuclear localization of Smad1 to inhibit Smad1-mediated ventx1.1 transcription. Foxd4l1.1 reduced the direct binding of Xbra and Smad1 on ventx1.1 promoter regions to block Xbra/Smad1-induced synergistic activation of ventx1.1 transcription. Collectively, Foxd4l1.1 negatively regulates transcription of a neural repressor ventx1.1 by multiple mechanisms in its exclusively occupied territory of neuroectoderm, and thus leading to primary neurogenesis. In conjunction with the results of our previous findings that ventx1.1 directly represses foxd4l1.1, the reciprocal repression of ventx1.1 and foxd4l1.1 is significant in at least in part specifying the mechanism for the non-neural versus neural ectoderm fate determination in Xenopus embryos.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Ectoderma/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Placa Neural/embriologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Ectoderma/metabolismo , Placa Neural/metabolismo , Regiões Promotoras Genéticas , Proteínas de Xenopus/genética , Xenopus laevis/genética
18.
Sensors (Basel) ; 20(5)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32120879

RESUMO

We implemented a mobile phone application of the pentagon drawing test (PDT), called mPDT, with a novel, automatic, and qualitative scoring method for the application based on U-Net (a convolutional network for biomedical image segmentation) coupled with mobile sensor data obtained with the mPDT. For the scoring protocol, the U-Net was trained with 199 PDT hand-drawn images of 512ⅹ512 resolution obtained via the mPDT in order to generate a trained model, Deep5, for segmenting a drawn right or left pentagon. The U-Net was also trained with 199 images of 512ⅹ512 resolution to attain the trained model, DeepLock, for segmenting an interlocking figure. Here, the epochs were iterated until the accuracy was greater than 98% and saturated. The mobile senor data primarily consisted of x and y coordinates, timestamps, and touch-events of all the samples with a 20 ms sampling period. The velocities were then calculated using the primary sensor data. With Deep5, DeepLock, and the sensor data, four parameters were extracted. These included the number of angles (0-4 points), distance/intersection between the two drawn figures (0-4 points), closure/opening of the drawn figure contours (0-2 points), and tremors detected (0-1 points). The parameters gave a scaling of 11 points in total. The performance evaluation for the mPDT included 230 images from subjects and their associated sensor data. The results of the performance test indicated, respectively, a sensitivity, specificity, accuracy, and precision of 97.53%, 92.62%, 94.35%, and 87.78% for the number of angles parameter; 93.10%, 97.90%, 96.09%, and 96.43% for the distance/intersection parameter; 94.03%, 90.63%, 92.61%, and 93.33% for the closure/opening parameter; and 100.00%, 100.00%, 100.00%, and 100.00% for the detected tremor parameter. These results suggest that the mPDT is very robust in differentiating dementia disease subtypes and is able to contribute to clinical practice and field studies.

19.
Anim Cells Syst (Seoul) ; 24(6): 359-370, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33456720

RESUMO

Activin, a member of the transforming growth factor (TGF-ß) superfamily, induces mesoderm, endoderm and neuro-ectoderm formation in Xenopus embryos. Despite several previous studies, the complicated gene regulatory network and genes involved in this induction await more elaboration. We identified expression of various fibroblast growth factor (FGF) genes in activin/smad2 treated animal cap explants (AC) of Xenopus embryos. Activin/smad2 increased fgf3/8 expression, which was reduced by co-injection of dominant negative activin receptor (DNAR) and dominant negative Fgf receptor (DNFR). Interestingly, activin/smad2 also increased expression of dual specificity phosphatase 1 (dusp1) which has been known to inhibit Fgf signaling. Dusp1 overexpression in dorsal marginal zone caused gastrulation defect and decreased Jnk/Erk phosphorylation as well as Smad1 linker region phosphorylation. Dusp1 decreased neural and organizer gene expression with increasing of endodermal and ventral gene expression in smad2 treated AC, indicating that dusp1 modulates germ layer specification. Dusp1 decreased neural gene expression in fgf8 treated AC, suggesting that Erk and/or Jnk phosphorylation may be involved in fgf8 induced neural induction. In addition, dusp1 decreased the reporter gene activities of activin response element (ARE) and increased it for bmp response element (BRE), indicating that dusp1 modulates two opposite morphogen signaling of dorsal (activin/Smad2) and ventral (bmp/Smad1) tracks, acting to fine tune the Fgf/Erk pathway.

20.
Sleep ; 43(3)2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31586200

RESUMO

OBJECTIVES: To investigate the association between zolpidem prescription and suicide attempts in people with depression. METHODS: A nationwide, population-based electronic medical records database from the Health Insurance Review & Assessment Service of South was used to investigate the incidence rate ratios (IRRs) of suicide attempts and probable suicide attempts in people with depression before and after zolpidem prescription using self-controlled case series design. RESULTS: In a total of 445 people who attempted suicide and 23 141 people who attempted probable suicide attempt, the IRRs of suicidal behavior during the risk periods before and after zolpidem prescription increased compared with those at the baseline. The IRRs gradually increased and peaked immediately before the prescription of zolpidem. The IRR was 70.06 (95% CI: 25.58-191.90) on day 2 before zolpidem prescription and 63.35 (95% CI: 22.99-174.59) on day 1 after zolpidem prescription in the suicide attempt group. The IRR was 24.07 (95% CI: 20.50-28.26) on the day before zolpidem prescription and 14.96 (95% CI: 12.21-18.34) on the day after zolpidem prescription in the probable suicide attempt group. The ratios declined eventually after zolpidem was prescribed. CONCLUSIONS: Although zolpidem prescription was associated with an increased risk of suicide attempts in people with depression, the risk increased and peaked immediately before zolpidem prescription. The risk declined gradually thereafter. This result indicates that the risk of suicide attempts increases at the time of zolpidem prescription. However, zolpidem prescription does not contribute to additional increase in the risk of suicide attempts.


Assuntos
Depressão , Tentativa de Suicídio , Humanos , Prescrições , República da Coreia/epidemiologia , Fatores de Risco , Zolpidem
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