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1.
Elife ; 122024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38635322

RESUMEN

Cortical folding is an important feature of primate brains that plays a crucial role in various cognitive and behavioral processes. Extensive research has revealed both similarities and differences in folding morphology and brain function among primates including macaque and human. The folding morphology is the basis of brain function, making cross-species studies on folding morphology important for understanding brain function and species evolution. However, prior studies on cross-species folding morphology mainly focused on partial regions of the cortex instead of the entire brain. Previously, our research defined a whole-brain landmark based on folding morphology: the gyral peak. It was found to exist stably across individuals and ages in both human and macaque brains. Shared and unique gyral peaks in human and macaque are identified in this study, and their similarities and differences in spatial distribution, anatomical morphology, and functional connectivity were also dicussed.


Asunto(s)
Encéfalo , Macaca , Animales , Humanos
2.
Nat Plants ; 10(3): 469-482, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38448725

RESUMEN

N6-methyladenosine (m6A) is the most abundant internal modification in eukaryotic mRNAs, yet how plants recognize this chemical modification to swiftly adjust developmental plasticity under environmental stresses remains unclear. Here we show that m6A mRNA modification and its reader protein EVOLUTIONARILY CONSERVED C-TERMINAL REGION 8 (ECT8) act together as a key checkpoint for negative feedback regulation of abscisic acid (ABA) signalling by sequestering the m6A-modified ABA receptor gene PYRABACTIN RESISTANCE 1-LIKE 7 (PYL7) via phase-separated ECT8 condensates in stress granules in response to ABA. This partially depletes PYL7 mRNA from its translation in the cytoplasm, thus reducing PYL7 protein levels and compromising ABA perception. The loss of ECT8 results in defective sequestration of m6A-modified PYL7 in stress granules and permits more PYL7 transcripts for translation. This causes overactivation of ABA-responsive genes and the consequent ABA-hypersensitive phenotypes, including drought tolerance. Overall, our findings reveal that m6A-mediated sequestration of PYL7 by ECT8 in stress granules negatively regulates ABA perception, thereby enabling prompt feedback regulation of ABA signalling to prevent plant cell overreaction to environmental stresses.


Asunto(s)
Adenosina/análogos & derivados , Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Retroalimentación , ARN Mensajero/genética , ARN Mensajero/metabolismo , Percepción , Regulación de la Expresión Génica de las Plantas , Estrés Fisiológico/genética , Sequías , Plantas Modificadas Genéticamente/genética
3.
Langmuir ; 40(12): 6424-6431, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38470109

RESUMEN

The self-assembly behaviors of aromatic carboxylic acids are commonly investigated at the liquid/solid interfaces because of their rigid skeletons and both hydrogen-bond donors and receptors. However, self-assemblies of aromatic carboxylic acids with low symmetry and interactions between carboxylic acid and pyridine derivatives are worth exploring. In this work, the self-assembled structural transitions of a kind of low-symmetric aromatic carboxylic acid (H4QDA) are regulated by the coadsorption of two pyridine derivatives (DPE and T4PT) with different symmetry, which are investigated by scanning tunneling microscopy under ambient conditions. For the H4QDA/DPE system, the grid structure appears. For the H4QDA/T4PT system, the coassembled morphologies display an obvious concentration dependence. With the increase of solution concentration of T4PT, three coassembled patterns (network structure, chiral linear structure, and brick-like structure) are observed. Corresponding structural models suggest that the O-H···N hydrogen bonds have great contributions to stabilizing these coassembled structures. Our studies will help to explore the complexity, diversity, and functionality of multiple component systems and are conducive to further understanding the underlying mechanisms in the assembly process.

4.
Langmuir ; 40(3): 1902-1908, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38194665

RESUMEN

Self-assemblies of two fluorenone-based derivatives (FE and FEC) consisting of a central 2,7-diphenyl-9-fluorenone polar moiety but differing in the flexible terminal groups were investigated by scanning tunneling microscopy (STM) at the 1-octanoic acid/HOPG interface under different concentrations and density functional theory calculation (DFT). STM results reveal a concentration-dependent polymorphic self-assembly behavior for FE, but without the presence of co-adsorbed solvents. As the concentration decreases, the dimer, bracket-like, and ribbon-like self-assembled structures were observed. On the contrary, FEC molecules assemble into only a type of oval-shaped morphology by the intermolecular N···H-O hydrogen bonds with the solvent molecules. Combined with DFT calculations, it can be deduced that the intermolecular van der Waals forces, dipole-dipole interactions, and hydrogen bonding are the main driving forces to stabilize the molecular packing of fluorenone-based polycatenars with strong polarity. Our work is of significance at the molecular level to further clarify the intermolecular interactions and conformational effects on the formation of molecular packing structures with liquid crystal property.

5.
bioRxiv ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-37546923

RESUMEN

Cortical folding is an important feature of primate brains that plays a crucial role in various cognitive and behavioral processes. Extensive research has revealed both similarities and differences in folding morphology and brain function among primates including macaque and human. The folding morphology is the basis of brain function, making cross-species studies on folding morphology important for understanding brain function and species evolution. However, prior studies on cross-species folding morphology mainly focused on partial regions of the cortex instead of the entire brain. Previously, we defined a whole-brain landmark based on folding morphology: the gyral peak. It was found to exist stably across individuals and ages in both human and macaque brains. In this study, we identified shared and unique gyral peaks in human and macaque, and investigated the similarities and differences in the spatial distribution, anatomical morphology, and functional connectivity of them.

6.
Neuroimage ; 280: 120344, 2023 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-37619794

RESUMEN

Genetic mechanisms have been hypothesized to be a major determinant in the formation of cortical folding. Although there is an increasing number of studies examining the heritability of cortical folding, most of them focus on sulcal pits rather than gyral peaks. Gyral peaks, which reflect the highest local foci on gyri and are consistent across individuals, remain unstudied in terms of heritability. To address this knowledge gap, we used high-resolution data from the Human Connectome Project (HCP) to perform classical twin analysis and estimate the heritability of gyral peaks across various brain regions. Our results showed that the heritability of gyral peaks was heterogeneous across different cortical regions, but relatively symmetric between hemispheres. We also found that pits and peaks are different in a variety of anatomic and functional measures. Further, we explored the relationship between the levels of heritability and the formation of cortical folding by utilizing the evolutionary timeline of gyrification. Our findings indicate that the heritability estimates of both gyral peaks and sulcal pits decrease linearly with the evolution timeline of gyrification. This suggests that the cortical folds which formed earlier during gyrification are subject to stronger genetic influences than the later ones. Moreover, the pits and peaks coupled by their time of appearance are also positively correlated in respect of their heritability estimates. These results fill the knowledge gap regarding genetic influences on gyral peaks and significantly advance our understanding of how genetic factors shape the formation of cortical folding. The comparison between peaks and pits suggests that peaks are not a simple morphological mirror of pits but could help complete the understanding of folding patterns.


Asunto(s)
Conocimiento , Gemelos , Humanos , Gemelos/genética
7.
Sci Rep ; 13(1): 13177, 2023 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-37580340

RESUMEN

The important mechanical parameters and their hierarchy in the growth and folding of the human brain have not been thoroughly understood. In this study, we developed a multiscale mechanical model to investigate how the interplay between initial geometrical undulations, differential tangential growth in the cortical plate, and axonal connectivity form and regulate the folding patterns of the human brain in a hierarchical order. To do so, different growth scenarios with bilayer spherical models that features initial undulations on the cortex and uniform or heterogeneous distribution of axonal fibers in the white matter were developed, statistically analyzed, and validated by the imaging observations. The results showed that the differential tangential growth is the inducer of cortical folding, and in a hierarchal order, high-amplitude initial undulations on the surface and axonal fibers in the substrate regulate the folding patterns and determine the location of gyri and sulci. The locations with dense axonal fibers after folding settle in gyri rather than sulci. The statistical results also indicated that there is a strong correlation between the location of positive (outward) and negative (inward) initial undulations and the locations of gyri and sulci after folding, respectively. In addition, the locations of 3-hinge gyral folds are strongly correlated with the initial positive undulations and locations of dense axonal fibers. As another finding, it was revealed that there is a correlation between the density of axonal fibers and local gyrification index, which has been observed in imaging studies but not yet fundamentally explained. This study is the first step in understanding the linkage between abnormal gyrification (surface morphology) and disruption in connectivity that has been observed in some brain disorders such as Autism Spectrum Disorder. Moreover, the findings of the study directly contribute to the concept of the regularity and variability of folding patterns in individual human brains.


Asunto(s)
Trastorno del Espectro Autista , Humanos , Corteza Cerebral/fisiología , Encéfalo/fisiología , Mapeo Encefálico , Axones , Imagen por Resonancia Magnética/métodos
8.
Dev Cell ; 58(8): 694-708.e4, 2023 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-37028425

RESUMEN

Angiosperms possess a life cycle with an alternation of sporophyte and gametophyte generations, which happens in plant organs like pistils. Rice pistils contain ovules and receive pollen for successful fertilization to produce grains. The cellular expression profile in rice pistils is largely unknown. Here, we show a cell census of rice pistils before fertilization through the use of droplet-based single-nucleus RNA sequencing. The ab initio marker identification validated by in situ hybridization assists with cell-type annotation, revealing cell heterogeneity between ovule- and carpel-originated cells. A comparison of 1N (gametophyte) and 2N (sporophyte) nuclei identifies the developmental path of germ cells in ovules with typical resetting of pluripotency before the sporophyte-gametophyte transition, while trajectory analysis of carpel-originated cells suggests previously neglected features of epidermis specification and style function. These findings gain a systems-level view of cellular differentiation and development of rice pistils before flowering and lay a foundation for understanding female reproductive development in plants.


Asunto(s)
Oryza , Oryza/metabolismo , Flores , Células Germinativas de las Plantas , Polen , Óvulo Vegetal/genética
9.
Plant Physiol ; 191(3): 2045-2063, 2023 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-36627133

RESUMEN

N 6-methyladenosine (m6A) modification on messenger RNAs (mRNAs) is deposited by evolutionarily conserved methyltransferases (writers). How individual m6A writers sculpt the overall landscape of the m6A methylome and the resulting biological impact in multicellular organisms remains unknown. Here, we systematically surveyed the quantitative m6A methylomes at single-nucleotide resolution and their corresponding transcriptomes in Arabidopsis (Arabidopsis thaliana) bearing respective impaired m6A writers. The m6A sites associated with the five Arabidopsis writers were located mostly within 3' untranslated regions with peaks at around 100 bp downstream of stop codons. m6A predominantly promoted the usage of distal poly(A) sites but had little effect on RNA splicing. Notably, impaired m6A writers resulted in hypomethylation and downregulation of transcripts encoding ribosomal proteins, indicating a possible correlation between m6A and protein translation. Besides the common effects on mRNA metabolism and biological functions uniquely exerted by different Arabidopsis m6A writers compared with their counterparts in human cell lines, our analyses also revealed the functional specificity of individual Arabidopsis m6A writers in plant development and response to stresses. Our findings thus reveal insights into the biological roles of various Arabidopsis m6A writers and their cognate counterparts in other multicellular m6A methyltransferase complexes.


Asunto(s)
Arabidopsis , Humanos , Metilación , Arabidopsis/genética , Arabidopsis/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Adenosina/genética , Adenosina/metabolismo , ARN/metabolismo
10.
J Phys Chem Lett ; 14(2): 489-498, 2023 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-36625786

RESUMEN

Fabricating tetraphenylethylene (TPE)-functionalized metal-organic frameworks (MOFs) with aggregation- induced emission on surfaces and understanding the growth mechanism have not yet been pursued. Herein, MOFs constructed via the Ullmann-type reaction of a C2-symmetry TPE derivative (p-BrTBE) on Au(111) and Cu(111) surfaces were thoroughly investigated using scanning tunneling microscopy. On a Au(111) surface, p-BrTBE molecules formed the self-assembled pattern at 298 K. Stepwise annealing led to a progressive evolution process, in which the stepwise debromination reaction led to organometallic intermediates, and surface-stabilized radicals and metal-organic networks were formed. By contrast, the relatively ordered MOFs were obtained by replacing the underlying substrate with the more catalytically active Cu(111) at 298 K. Density functional theory calculations demonstrated that the formation of different networks on Au(111) and Cu(111) was determined by the different conformations of the TBE unit on the different substrates due to the different adsorption energy.

11.
Cereb Cortex ; 33(11): 6708-6722, 2023 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-36646465

RESUMEN

Cortical folding patterns are related to brain function, cognition, and behavior. Since the relationship has not been fully explained on a coarse scale, many efforts have been devoted to the identification of finer grained cortical landmarks, such as sulcal pits and gyral peaks, which were found to remain invariant across subjects and ages and the invariance may be related to gene mediated proto-map. However, gyral peaks were only investigated on macaque monkey brains, but not on human brains where the investigation is challenged due to high inter-individual variabilities. To this end, in this work, we successfully identified 96 gyral peaks both on the left and right hemispheres of human brains, respectively. These peaks are spatially consistent across individuals. Higher or sharper peaks are more consistent across subjects. Both structural and functional graph metrics of peaks are significantly different from other cortical regions, and more importantly, these nodal graph metrics are anti-correlated with the spatial consistency metrics within peaks. In addition, the distribution of peaks and various cortical anatomical, structural/functional connective features show hemispheric symmetry. These findings provide new clues to understanding the cortical landmarks, as well as their relationship with brain functions, cognition, behavior in both healthy and aberrant brains.


Asunto(s)
Encéfalo , Imagen por Resonancia Magnética , Animales , Humanos , Membrana Celular , Corteza Cerebral , Macaca
12.
Hum Brain Mapp ; 43(15): 4540-4555, 2022 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-35713202

RESUMEN

Cerebral cortex development undergoes a variety of processes, which provide valuable information for the study of the developmental mechanism of cortical folding as well as its relationship to brain structural architectures and brain functions. Despite the variability in the anatomy-function relationship on the higher-order cortex, recent studies have succeeded in identifying typical cortical landmarks, such as sulcal pits, that bestow specific functional and cognitive patterns and remain invariant across subjects and ages with their invariance being related to a gene-mediated proto-map. Inspired by the success of these studies, we aim in this study at defining and identifying novel cortical landmarks, termed gyral peaks, which are the local highest foci on gyri. By analyzing data from 156 MRI scans of 32 macaque monkeys with the age spanned from 0 to 36 months, we identified 39 and 37 gyral peaks on the left and right hemispheres, respectively. Our investigation suggests that these gyral peaks are spatially consistent across individuals and relatively stable within the age range of this dataset. Moreover, compared with other gyri, gyral peaks have a thicker cortex, higher mean curvature, more pronounced hub-like features in structural connective networks, and are closer to the borders of structural connectivity-based cortical parcellations. The spatial distribution of gyral peaks was shown to correlate with that of other cortical landmarks, including sulcal pits. These results provide insights into the spatial arrangement and temporal development of gyral peaks as well as their relation to brain structure and function.


Asunto(s)
Encéfalo , Macaca , Animales , Encéfalo/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos
13.
Methods ; 203: 125-138, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35436514

RESUMEN

N6-methyladenosine (m6A) is the most abundant eukaryotic modification internal mRNA, which plays the crucial roles in the occurrence and development of cancer. However, current knowledge about m6A-mediated functional circuit and key genes targeted by m6A methylation in cancer is mostly elusive. Thus, here we proposed a novel network-based approach (called m6Acancer-Net) to identify m6A-mediated driver genes and their associated network in specific type of cancer, such as acute myeloid leukemia. m6A-mediated cancer driver genes are defined as genes mediated by m6A methylation, significantly mutated, and functionally interacted in cancer. m6Acancer-Net identified the m6A-mediated cancer driver genes by combining gene functional interaction network with RNA methylation, gene expression and mutation information. A cancer-specific gene-site heterogeneous network was firstly constructed by connecting the m6A site co-methylation network with the functional interaction pruned gene co-expression network generated from large scale gene expression profile of specific cancer. Then, the functional m6A-mediated genes were identified by selecting the m6A regulators as seed genes to perform the random walk with restart algorithm on the gene-site heterogeneous network. Finally, m6A-mediated cancer driver gene subnetworks were constructed by performing the heat diffusion of mutation frequency for functional m6A-mediated genes in protein-protein interaction networks. The experimental results of m6Acancer-Net on the acute myeloid leukemia (AML) and glioblastoma multiforme (GBM) data from TCGA project show that the m6A-mediated caner driver genes identified by m6Acancer-Net are targeted by m6A regulators, and mediate significant cancer-related pathways. They play crucial roles in development and prognostic stratification of cancer. Moreover, 15 m6A-mediated cancer driver genes identified in AML are validated by literatures to mediate AML progress, and 14 m6A-mediated cancer driver genes identified in GBM are validated by literatures to participate in development of GBM. m6Acancer-Net is reliable to identify the functionally significant m6A-mediated driver genes in specific cancer, and it can effectively facilitate the understanding of regulatory and therapeutic mechanism of cancer driver genes in epitranscriptome layer.


Asunto(s)
Redes Reguladoras de Genes , Glioblastoma , Algoritmos , Glioblastoma/genética , Humanos , Mutación , Mapas de Interacción de Proteínas/genética
14.
Methods ; 203: 167-178, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35314342

RESUMEN

N6-methyladenosine (m6A) is the most abundant form of mRNA modification and plays an important role in regulating gene expression. However, the mechanisms of m6A regulated gene expression in cell or condition specific, are still poorly understood. Even though, some methods are able to predict m6A regulated expression (m6A-reg-exp) genes in specific context, they don't introduce the m6A reader binding information, while this information can help to predict m6A-reg-exp genes and more clearly to explain the mechanisms of m6A-mediated gene expression process. Thus, by integrating m6A sites and reader binding information, we proposed a novel method (called m6Aexpress-Reader) to predict m6A-reg-exp genes from limited MeRIP-seq data in specific context. m6Aexpress-Reader adopts the reader binding signal strength to weight the posterior distribution of the estimated regulatory coefficients for enhancing the prediction power. By using m6Aexpress-Reader, we found the complex characteristic of m6A on gene expression regulation and the distinct regulated pattern of m6A-reg-exp genes with different reader binding. m6A readers, YTHDF2 or IGF2BP1/3 all play an important role in various cancers and the key cancer pathways. In addition, m6Aexpress-Reader reveals the distinct m6A regulated mode of reader targeted genes in cancer. m6Aexpress-Reader could be a useful tool for studying the m6A regulation on reader target genes in specific context and it can be freely accessible at: https://github.com/NWPU-903PR/m6AexpressReader.


Asunto(s)
Neoplasias , Proteínas de Unión al ARN , Adenosina/genética , Adenosina/metabolismo , Regulación de la Expresión Génica , Humanos , Neoplasias/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo
15.
Adv Sci (Weinh) ; 9(6): e2103628, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34989479

RESUMEN

N6 -methyladenosine (m6 A) mRNA modification represents the most widespread form of internal modifications in eukaryotic mRNAs. In the model plant Arabidopsis thaliana, those known methyltransferases mainly deposit m6 A at their target transcripts near the stop codon or in the 3' untranslated region. Here, it is reported that FIONA1 (FIO1), a human METTL16 ortholog, acts as a hitherto unknown m6 A methyltransferase that determines m6 A modifications at over 2000 Arabidopsis transcripts predominantly in the coding region. Mutants of FIO1 show a decrease in global m6 A mRNA methylation levels and an early-flowering phenotype. Nanopore direct RNA sequencing reveals that FIO1 is required for establishing appropriate levels of m6 A preferentially in the coding sequences of a subset of protein-coding transcripts, which is associated with changes in transcript abundance and alternative polyadenylation. It is further demonstrated that FIO1-mediated m6 A methylation determines the mRNA abundance of a central flowering integrator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and its upstream regulators, thus preventing premature flowering. The findings reveal that FIO1 acts as a unique m6 A methyltransferase that mainly modifies the coding regions of transcripts, which underlies the key developmental transition from vegetative to reproductive growth in plants.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulación del Desarrollo de la Expresión Génica/genética , Genes de Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo
16.
Brain Struct Funct ; 227(3): 1013-1029, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34989870

RESUMEN

Postnatal development of cerebral cortex is associated with a variety of neuronal processes and is thus critical to development of brain function and cognition. Longitudinal changes of cortical morphology and topology, such as postnatal cortical thinning and flattening have been widely studied. However, thorough and systematic investigation of such cortical change, including how to quantify it from multiple spatial directions and how to relate it to surface topology, is rarely found. In this work, based on a longitudinal macaque neuroimaging dataset, we quantified local changes in gyral white matter's surface area and sulcal depth during early development. We also investigated how these two metrics are coupled and how this coupling is linked to cortical surface topology, underlying white matter, and positions of functional areas. Semi-parametric generalized additive models were adopted to quantify the longitudinal changes of surface area (A) and sulcal depth (D), and the coupling patterns between them. This resulted in four classes of regions, according to how they change compared with global change throughout early development: slower surface area change and slower sulcal depth change (slowA_slowD), slower surface area change and faster sulcal depth change (slowA_fastD), faster surface area change and slower sulcal depth change (fastA_slowD), and faster surface area change and faster sulcal depth change (fastA_fastD). We found that cortex-related metrics, including folding pattern and cortical thickness, vary along slowA_fastD-fastA_slowD axis, and structural connection-related metrics vary along fastA_fastD-slowA_slowD axis, with which brain functional sites align better. It is also found that cortical landmarks, including sulcal pits and gyral hinges, spatially reside on the borders of the four patterns. These findings shed new lights on the relationship between cortex development, surface topology, axonal wiring pattern and brain functions.


Asunto(s)
Macaca , Sustancia Blanca , Animales , Axones , Corteza Cerebral/anatomía & histología , Imagen por Resonancia Magnética/métodos
17.
Nucleic Acids Res ; 49(20): e116, 2021 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-34417605

RESUMEN

N6-methyladenosine (m6A) is the most abundant form of mRNA modification and controls many aspects of RNA metabolism including gene expression. However, the mechanisms by which m6A regulates cell- and condition-specific gene expression are still poorly understood, partly due to a lack of tools capable of identifying m6A sites that regulate gene expression under different conditions. Here we develop m6A-express, the first algorithm for predicting condition-specific m6A regulation of gene expression (m6A-reg-exp) from limited methylated RNA immunoprecipitation sequencing (MeRIP-seq) data. Comprehensive evaluations of m6A-express using simulated and real data demonstrated its high prediction specificity and sensitivity. When only a few MeRIP-seq samples may be available for the cellular or treatment conditions, m6A-express is particularly more robust than the log-linear model. Using m6A-express, we reported that m6A writers, METTL3 and METTL14, competitively regulate the transcriptional processes by mediating m6A-reg-exp of different genes in Hela cells. In contrast, METTL3 induces different m6A-reg-exp of a distinct group of genes in HepG2 cells to regulate protein functions and stress-related processes. We further uncovered unique m6A-reg-exp patterns in human brain and intestine tissues, which are enriched in organ-specific processes. This study demonstrates the effectiveness of m6A-express in predicting condition-specific m6A-reg-exp and highlights the complex, condition-specific nature of m6A-regulation of gene expression.


Asunto(s)
Adenosina/análogos & derivados , Procesamiento Postranscripcional del ARN , Análisis de Secuencia de ARN/métodos , Adenosina/metabolismo , Encéfalo/metabolismo , Células HeLa , Células Hep G2 , Humanos , Mucosa Intestinal/metabolismo
18.
Comput Struct Biotechnol J ; 19: 3015-3026, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34136099

RESUMEN

RNA modifications, in particular N 6-methyladenosine (m6A), participate in every stages of RNA metabolism and play diverse roles in essential biological processes and disease pathogenesis. Thanks to the advances in sequencing technology, tens of thousands of RNA modification sites can be identified in a typical high-throughput experiment; however, it remains a major challenge to decipher the functional relevance of these sites, such as, affecting alternative splicing, regulation circuit in essential biological processes or association to diseases. As the focus of RNA epigenetics gradually shifts from site discovery to functional studies, we review here recent progress in functional annotation and prediction of RNA modification sites from a bioinformatics perspective. The review covers naïve annotation with associated biological events, e.g., single nucleotide polymorphism (SNP), RNA binding protein (RBP) and alternative splicing, prediction of key sites and their regulatory functions, inference of disease association, and mining the diagnosis and prognosis value of RNA modification regulators. We further discussed the limitations of existing approaches and some future perspectives.

19.
Bioinformatics ; 37(22): 4277-4279, 2021 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-33974000

RESUMEN

MOTIVATION: N 6-methyladenosine (m6A) is the most abundant mammalian mRNA methylation with versatile functions. To date, although a number of bioinformatics tools have been developed for location discovery of m6A modification, functional understanding is still quite limited. As the focus of RNA epigenetics gradually shifts from site discovery to functional studies, there is an urgent need for user-friendly tools to identify and explore the functional relevance of context-specific m6A methylation to gain insights into the epitranscriptome layer of gene expression regulation. RESULTS: We introduced here Funm6AViewer, a novel platform to identify, prioritize and visualize the functional gene interaction networks mediated by dynamic m6A RNA methylation unveiled from a case control study. By taking the differential RNA methylation data and differential gene expression data, both of which can be inferred from the widely used MeRIP-seq data, as the inputs, Funm6AViewer enables a series of analysis, including: (i) examining the distribution of differential m6A sites, (ii) prioritizing the genes mediated by dynamic m6A methylation and (iii) characterizing functionally the gene regulatory networks mediated by condition-specific m6A RNA methylation. Funm6AViewer should effectively facilitate the understanding of the epitranscriptome circuitry mediated by this reversible RNA modification. AVAILABILITY AND IMPLEMENTATION: Funm6AViewer is available both as a convenient web server (https://www.xjtlu.edu.cn/biologicalsciences/funm6aviewer) with graphical interface and as an independent R package (https://github.com/NWPU-903PR/Funm6AViewer) for local usage. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Epigénesis Genética , ARN , Animales , Metilación , Estudios de Casos y Controles , ARN/metabolismo , Redes Reguladoras de Genes , Adenosina/metabolismo , Mamíferos/genética
20.
Methods ; 192: 120-130, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33484826

RESUMEN

The survival rate of cancer has increased significantly during the past two decades for breast, prostate, testicular, and colon cancer, while the brain and pancreatic cancers have a much lower median survival rate that has not improved much over the last forty years. This has imposed the challenge of finding gene markers for early cancer detection and treatment strategies. Different methods including regression-based Cox-PH, artificial neural networks, and recently deep learning algorithms have been proposed to predict the survival rate for cancers. We established in this work a novel graph convolution neural network (GCNN) approach called Surv_GCNN to predict the survival rate for 13 different cancer types using the TCGA dataset. For each cancer type, 6 Surv_GCNN models with graphs generated by correlation analysis, GeneMania database, and correlation + GeneMania were trained with and without clinical data to predict the risk score (RS). The performance of the 6 Surv_GCNN models was compared with two other existing models, Cox-PH and Cox-nnet. The results showed that Cox-PH has the worst performance among 8 tested models across the 13 cancer types while Surv_GCNN models with clinical data reported the best overall performance, outperforming other competing models in 7 out of 13 cancer types including BLCA, BRCA, COAD, LUSC, SARC, STAD, and UCEC. A novel network-based interpretation of Surv_GCNN was also proposed to identify potential gene markers for breast cancer. The signatures learned by the nodes in the hidden layer of Surv_GCNN were identified and were linked to potential gene markers by network modularization. The identified gene markers for breast cancer have been compared to a total of 213 gene markers from three widely cited lists for breast cancer survival analysis. About 57% of gene markers obtained by Surv_GCNN with correlation + GeneMania graph either overlap or directly interact with the 213 genes, confirming the effectiveness of the identified markers by Surv_GCNN.


Asunto(s)
Redes Neurales de la Computación , Algoritmos , Neoplasias de la Mama/genética , Humanos , Masculino , Tasa de Supervivencia
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