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1.
Braz J Biol ; 84: e277974, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38808784

RESUMO

Maize (Zea mays L.) is of socioeconomic importance as an essential food for human and animal nutrition. However, cereals are susceptible to attack by mycotoxin-producing fungi, which can damage health. The methods most commonly used to detect and quantify mycotoxins are expensive and time-consuming. Therefore, alternative non-destructive methods are required urgently. The present study aimed to use near-infrared spectroscopy with hyperspectral imaging (NIR-HSI) and multivariate image analysis to develop a rapid and accurate method for quantifying fumonisins in whole grains of six naturally contaminated maize cultivars. Fifty-eight samples, each containing 40 grains, were subjected to NIR-HSI. These were subsequently divided into calibration (38 samples) and prediction sets (20 samples) based on the multispectral data obtained. The averaged spectra were subjected to various pre-processing techniques (standard normal variate (SNV), first derivative, or second derivative). The most effective pre-treatment performed on the spectra was SNV. Partial least squares (PLS) models were developed to quantify the fumonisin content. The final model presented a correlation coefficient (R2) of 0.98 and root mean square error of calibration (RMSEC) of 508 µg.kg-1 for the calibration set, an R2 of 0.95 and root mean square error of prediction (RMSEP) of 508 µg.kg-1 for the test validation set and a ratio of performance to deviation of 4.7. It was concluded that NIR-HSI with partial least square regression is a rapid, effective, and non-destructive method to determine the fumonisin content in whole maize grains.


Assuntos
Fumonisinas , Imageamento Hiperespectral , Espectroscopia de Luz Próxima ao Infravermelho , Zea mays , Zea mays/química , Fumonisinas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Imageamento Hiperespectral/métodos , Reprodutibilidade dos Testes , Quimiometria/métodos
2.
Int J Mol Sci ; 25(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38791219

RESUMO

The trophoblast cells are responsible for the transfer of nutrients between the mother and the foetus and play a major role in placental endocrine function by producing and releasing large amounts of hormones and growth factors. Syncytiotrophoblast cells (STB), formed by the fusion of mononuclear cytotrophoblasts (CTB), constitute the interface between the foetus and the mother and are essential for all of these functions. We performed transcriptome analysis of human placental samples from two control groups-live births (LB), and stillbirths (SB) with a clinically recognised cause-and from our study group, idiopathic stillbirths (iSB). We identified 1172 DEGs in iSB, when comparing with the LB group; however, when we compared iSB with the SB group, only 15 and 12 genes were down- and upregulated in iSB, respectively. An assessment of these DEGs identified 15 commonly downregulated genes in iSB. Among these, several syncytiotrophoblast markers, like genes from the PSG and CSH families, as well as ALPP, KISS1, and CRH, were significantly downregulated in placental samples from iSB. The transcriptome analysis revealed underlying differences at a molecular level involving the syncytiotrophoblast. This suggests that defects in the syncytial layer may underlie unexplained stillbirths, therefore offering insights to improve clinical obstetrics practice.


Assuntos
Biomarcadores , Regulação para Baixo , Placenta , Natimorto , Trofoblastos , Humanos , Feminino , Trofoblastos/metabolismo , Trofoblastos/patologia , Gravidez , Placenta/metabolismo , Natimorto/genética , Biomarcadores/metabolismo , Perfilação da Expressão Gênica , Transcriptoma
4.
ACS Omega ; 9(19): 21245-21259, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38764615

RESUMO

Semiconducting nanoparticles (SNPs) have garnered significant attention for their role in photocatalysis technology, offering a cost-effective and highly efficient method for breaking down organic dyes. Of particular significance within SNP-based photocatalysis are tunable band gap TiO2 nanoparticles (NPs), which demonstrate remarkable enhancement in photocatalytic efficiency. In the present work, we introduce an approach for the synthesis of TiO2 NPs using kappa-carrageenan (κ-carrageenan), not just as a reducing and stabilizing agent but as a dopant for the resulting TiO2 NPs. During the synthesis of TiO2 NPs in the presence of sulfate-rich carrageenan, the process predominantly leaves residual sulfur and carbon. The presence of residual carbon, in conjunction with sulfur doping, as indicated by fast FTIR spectra, XPS, and EDX, leads to a significant reduction in the band gap of the resulting composite to 2.71 eV. The reduction of composite band gap yields remarkable degradation of methylene blue (99.97%) and methyl orange (97.84%). This work presents an eco-friendly and highly effective solution for the swift removal of environmentally harmful organic dyes.

5.
Psychol Sci ; : 9567976241243370, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662413

RESUMO

Both homophily and heterophily are observed in humans. Homophily reinforces homogeneous social networks, and heterophily creates new experiences and collaborations. However, at the extremes, high levels of homophily can cultivate prejudice toward out-groups, whereas high levels of heterophily can weaken in-group support. Using data from 24,726 adults (M = 46 years; selected from 10,398 English neighborhoods) and the composition of their social networks based on age, ethnicity, income, and education, we tested the hypothesis that a middle ground between homophily and heterophily could be the most beneficial for individuals. We found that network homophily, mediated by perceived social cohesion, is associated with higher levels of subjective well-being but that there are diminishing returns, because at a certain point increasing network homophily is associated with lower social cohesion and, in turn, lower subjective well-being. Our results suggest that building diverse social networks provides benefits that cannot be attained by homogeneous networks.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38529620

RESUMO

ABSTRACT: Despite new effective medications, patients with SMA types 1-3 can continue to have inadequate cough flows to prevent episodes of acute respiratory failure. Ventilator unweanable intubated patients are thought to require tracheostomy tubes. As a result, potentially beneficial medications may be discontinued and patients die despite receiving these medications. Three cases are presented of medically treated, physically strengthening children, with SMA type 1. All three subsequently died or underwent tracheotomy. However, there is no evidence of extubation attempts to noninvasive ventilatory support settings or optimal mechanical insufflation-exsufflation despite this option being described to be over 98% successful for extubating unweanable medically untreated children with SMA1.

7.
Front Vet Sci ; 11: 1347107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38379923

RESUMO

Three-dimensional (3D) printed models can improve the understanding of the structural anatomic changes in cases of temporomandibular joint ankylosis and pseudoankylosis leading to closed jaw locking. Their use in pre-surgical planning and intraoperative guidance has been reported, contributing to the predictability and success of these surgery procedures, which can be quite complex, especially in small animal patients. The use and production of 3D tools and models remain challenging and are so far limited to institutions with high (economical and human) resources. This study aims to propose simplified workflows using open-source software to facilitate an in-house 3D printing process. To illustrate this, three cases of temporomandibular joint ankylosis and one of pseudoankylosis were reviewed, where in-house 3D printed models were used for client communication and surgical management. The 3D models were segmented from computed tomography and printed via stereolithography. They were used to support discussion with clients (n = 4), to allow surgeons to pre-surgical plan and practice (n = 4) and for intraoperative guidance during surgery (n = 2). Surgical cutting guides were produced in one case to improve precision and define more accurately osteotomy lines. It is essential to consider the initial time and financial investment required for establishing an in-house 3D printing production, particularly when there is a need to produce biocompatible tools, such as surgical cutting guides. However, efficient and streamlined workflows encourage the integration of this technology, by accelerating the printing process and reducing the steep learning curves, while open-source software enhances accessibility to these resources.

8.
EMBO Mol Med ; 16(1): 132-157, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38177536

RESUMO

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening condition associated with Marfan syndrome (MFS), a disease caused by fibrillin-1 gene mutations. While various conditions causing TAAD exhibit aortic accumulation of the proteoglycans versican (Vcan) and aggrecan (Acan), it is unclear whether these ECM proteins are involved in aortic disease. Here, we find that Vcan, but not Acan, accumulated in Fbn1C1041G/+ aortas, a mouse model of MFS. Vcan haploinsufficiency protected MFS mice against aortic dilation, and its silencing reverted aortic disease by reducing Nos2 protein expression. Our results suggest that Acan is not an essential contributor to MFS aortopathy. We further demonstrate that Vcan triggers Akt activation and that pharmacological Akt pathway inhibition rapidly regresses aortic dilation and Nos2 expression in MFS mice. Analysis of aortic tissue from MFS human patients revealed accumulation of VCAN and elevated pAKT-S473 staining. Together, these findings reveal that Vcan plays a causative role in MFS aortic disease in vivo by inducing Nos2 via Akt activation and identify Akt signaling pathway components as candidate therapeutic targets.


Assuntos
Aneurisma da Aorta Torácica , Doenças da Aorta , Dissecção Aórtica , Azidas , Desoxiglucose , Síndrome de Marfan , Animais , Humanos , Camundongos , Aneurisma da Aorta Torácica/complicações , Aneurisma da Aorta Torácica/genética , Aneurisma da Aorta Torácica/metabolismo , Doenças da Aorta/complicações , Desoxiglucose/análogos & derivados , Síndrome de Marfan/complicações , Síndrome de Marfan/genética , Síndrome de Marfan/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Versicanas/metabolismo
9.
Epigenetics Chromatin ; 16(1): 39, 2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37845773

RESUMO

BACKGROUND: Vitamin C (vitC) enhances the activity of 2-oxoglutarate-dependent dioxygenases, including TET enzymes, which catalyse DNA demethylation, and Jumonji-domain histone demethylases. The epigenetic remodelling promoted by vitC improves the efficiency of induced pluripotent stem cell derivation, and is required to attain a ground-state of pluripotency in embryonic stem cells (ESCs) that closely mimics the inner cell mass of the early blastocyst. However, genome-wide DNA and histone demethylation can lead to upregulation of transposable elements (TEs), and it is not known how vitC addition in culture media affects TE expression in pluripotent stem cells. RESULTS: Here we show that vitC increases the expression of several TE families, including evolutionarily young LINE-1 (L1) elements, in mouse ESCs. We find that TET activity is dispensable for L1 upregulation, and that instead it occurs largely as a result of H3K9me3 loss mediated by KDM4A/C histone demethylases. Despite increased L1 levels, we did not detect increased somatic insertion rates in vitC-treated cells. Notably, treatment of human ESCs with vitC also increases L1 protein levels, albeit through a distinct, post-transcriptional mechanism. CONCLUSION: VitC directly modulates the expression of mouse L1s and other TEs through epigenetic mechanisms, with potential for downstream effects related to the multiple emerging roles of L1s in cellular function.


Assuntos
Ácido Ascórbico , Células-Tronco Embrionárias Murinas , Humanos , Animais , Camundongos , Ácido Ascórbico/farmacologia , Células-Tronco Embrionárias Murinas/metabolismo , Elementos Nucleotídeos Longos e Dispersos , Metilação de DNA , Histona Desmetilases/metabolismo , DNA/metabolismo , Desmetilação , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo
10.
Stem Cell Reports ; 18(11): 2154-2173, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37802073

RESUMO

Our understanding of how STAG proteins contribute to cell identity and disease have largely been studied from the perspective of chromosome topology and protein-coding gene expression. Here, we show that STAG1 is the dominant paralog in mouse embryonic stem cells (mESCs) and is required for pluripotency. mESCs express a wide diversity of naturally occurring Stag1 isoforms, resulting in complex regulation of both the levels of STAG paralogs and the proportion of their unique terminal ends. Skewing the balance of these isoforms impacts cell identity. We define a novel role for STAG1, in particular its N-terminus, in regulating repeat expression, nucleolar integrity, and repression of the two-cell (2C) state to maintain mESC identity. Our results move beyond protein-coding gene regulation via chromatin loops to new roles for STAG1 in nucleolar structure and function, and offer fresh perspectives on how STAG proteins, known to be cancer targets, contribute to cell identity and disease.


Assuntos
Células-Tronco Embrionárias Murinas , Neoplasias , Animais , Camundongos , Diferenciação Celular , Cromatina/genética , Cromatina/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Neoplasias/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-37603474

RESUMO

With the rise of machine learning, hyperspectral image (HSI) unmixing problems have been tackled using learning-based methods. However, physically meaningful unmixing results are not guaranteed without proper guidance. In this work, we propose an unsupervised framework inspired by deep image prior (DIP) that can be used for both linear and nonlinear blind unmixing models. The framework consists of three modules: 1) an Endmember estimation module using DIP (EDIP); 2) an Abundance estimation module using DIP (ADIP); and 3) a mixing module (MM). EDIP and ADIP modules generate endmembers and abundances, respectively, while MM produces a reconstruction of the HSI observations based on the postulated unmixing model. We introduce a composite loss function that applies to both linear and nonlinear unmixing models to generate meaningful unmixing results. In addition, we propose an adaptive loss weight strategy for better unmixing results in nonlinear mixing scenarios. The proposed methods outperform state-of-the-art unmixing algorithms in extensive experiments conducted on both synthetic and real datasets.

12.
Cell Death Dis ; 14(8): 500, 2023 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-37542079

RESUMO

In the adult mammalian brain, neural stem cells (NSCs) located in highly restricted niches sustain the generation of new neurons that integrate into existing circuits. A reduction in adult neurogenesis is linked to ageing and neurodegeneration, whereas dysregulation of proliferation and survival of NSCs have been hypothesized to be at the origin of glioma. Thus, unravelling the molecular underpinnings of the regulated activation that NSCs must undergo to proliferate and generate new progeny is of considerable relevance. Current research has identified cues promoting or restraining NSCs activation. Yet, whether NSCs depend on external signals to survive or if intrinsic factors establish a threshold for sustaining their viability remains elusive, even if this knowledge could involve potential for devising novel therapeutic strategies. Kidins220 (Kinase D-interacting substrate of 220 kDa) is an essential effector of crucial pathways for neuronal survival and differentiation. It is dramatically altered in cancer and in neurological and neurodegenerative disorders, emerging as a regulatory molecule with important functions in human disease. Herein, we discover severe neurogenic deficits and hippocampal-based spatial memory defects accompanied by increased neuroblast death and high loss of newly formed neurons in Kidins220 deficient mice. Mechanistically, we demonstrate that Kidins220-dependent activation of AKT in response to EGF restraints GSK3 activity preventing NSCs apoptosis. We also show that NSCs with Kidins220 can survive with lower concentrations of EGF than the ones lacking this molecule. Hence, Kidins220 levels set a molecular threshold for survival in response to mitogens, allowing adult NSCs growth and expansion. Our study identifies Kidins220 as a key player for sensing the availability of growth factors to sustain adult neurogenesis, uncovering a molecular link that may help paving the way towards neurorepair.


Assuntos
Células-Tronco Adultas , Células-Tronco Neurais , Adulto , Animais , Humanos , Camundongos , Células-Tronco Adultas/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Hipocampo/metabolismo , Mamíferos , Células-Tronco Neurais/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo
13.
Curr Res Neurobiol ; 4: 100086, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37397806

RESUMO

Modern neuroscience approaches including optogenetics, calcium imaging, and other genetic manipulations have facilitated our ability to dissect specific circuits in rodent models to study their role in neurological disease. These approaches regularly use viral vectors to deliver genetic cargo (e.g., opsins) to specific tissues and genetically-engineered rodents to achieve cell-type specificity. However, the translatability of these rodent models, cross-species validation of identified targets, and translational efficacy of potential therapeutics in larger animal models like nonhuman primates remains difficult due to the lack of efficient primate viral vectors. A refined understanding of the nonhuman primate nervous system promises to deliver insights that can guide the development of treatments for neurological and neurodegenerative diseases. Here, we outline recent advances in the development of adeno-associated viral vectors for optimized use in nonhuman primates. These tools promise to help open new avenues for study in translational neuroscience and further our understanding of the primate brain.

14.
Entropy (Basel) ; 25(7)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37510010

RESUMO

It is well-known that a neural network learning process-along with its connections to fitting, compression, and generalization-is not yet well understood. In this paper, we propose a novel approach to capturing such neural network dynamics using information-bottleneck-type techniques, involving the replacement of mutual information measures (which are notoriously difficult to estimate in high-dimensional spaces) by other more tractable ones, including (1) the minimum mean-squared error associated with the reconstruction of the network input data from some intermediate network representation and (2) the cross-entropy associated with a certain class label given some network representation. We then conducted an empirical study in order to ascertain how different network models, network learning algorithms, and datasets may affect the learning dynamics. Our experiments show that our proposed approach appears to be more reliable in comparison with classical information bottleneck ones in capturing network dynamics during both the training and testing phases. Our experiments also reveal that the fitting and compression phases exist regardless of the choice of activation function. Additionally, our findings suggest that model architectures, training algorithms, and datasets that lead to better generalization tend to exhibit more pronounced fitting and compression phases.

15.
Diagnostics (Basel) ; 13(14)2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37510058

RESUMO

Because most of the recognized causes of superior gluteal nerve (SGN) injury are iatrogenic, detailed knowledge of the anatomy of the SGN is crucial to prevent its injury associated with surgical procedures. This study aims to describe the precise location of SGN or its branches at the greater sciatic foramen, measure the distances of these neural structures to palpable bony landmarks, and evaluate the possible correlation between these parameters and pelvis size. Twenty human cadaveric hemipelvises were studied. After dissection to expose the SGN or its branches at the greater sciatic foramen, the distances from these neural structures to the greater trochanter (GT), to the anterior superior iliac spine (ASIS), to the posterior superior iliac spine (PSIS), to the ischial tuberosity (IT), and to the greater sciatic notch apex were measured. We found that at the greater sciatic foramen, the SGN emerges as a common trunk in 75% of hemipelvises, and already divided in its superior and inferior branches in 25% of hemipelvises. When the SGN exits the pelvis as a common trunk, it does so, in most cases, in contact with the bone at the apex of the greater sciatic notch or superior to the level of the apex. The median distance from the SGN at the greater sciatic notch to the PSIS, ASIS, GT and IT is 7.6 cm, 10.9 cm, 7.5 cm and 10.8 cm, respectively. We found a positive correlation between some of the analyzed parameters and the size of the pelvis. The anatomical data of this study may serve as pivotal guides during orthopedic pelvic surgery, contributing to minimize SNG iatrogenic lesions with significant implications in the patient's quality of life.

16.
Nat Nanotechnol ; 18(10): 1241-1251, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37430038

RESUMO

Crossing the blood-brain barrier in primates is a major obstacle for gene delivery to the brain. Adeno-associated viruses (AAVs) promise robust, non-invasive gene delivery from the bloodstream to the brain. However, unlike in rodents, few neurotropic AAVs efficiently cross the blood-brain barrier in non-human primates. Here we report on AAV.CAP-Mac, an engineered variant identified by screening in adult marmosets and newborn macaques, which has improved delivery efficiency in the brains of multiple non-human primate species: marmoset, rhesus macaque and green monkey. CAP-Mac is neuron biased in infant Old World primates, exhibits broad tropism in adult rhesus macaques and is vasculature biased in adult marmosets. We demonstrate applications of a single, intravenous dose of CAP-Mac to deliver functional GCaMP for ex vivo calcium imaging across multiple brain areas, or a cocktail of fluorescent reporters for Brainbow-like labelling throughout the macaque brain, circumventing the need for germline manipulations in Old World primates. As such, CAP-Mac is shown to have potential for non-invasive systemic gene transfer in the brains of non-human primates.


Assuntos
Encéfalo , Callithrix , Humanos , Animais , Recém-Nascido , Chlorocebus aethiops , Macaca mulatta/genética , Callithrix/genética , Encéfalo/fisiologia , Técnicas de Transferência de Genes , Neurônios , Vetores Genéticos/genética
17.
Front Cell Dev Biol ; 11: 1209928, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37440923

RESUMO

One-carbon metabolism, including the folate cycle, has a crucial role in fetal development though its molecular function is complex and unclear. The hypomorphic Mtrr gt allele is known to disrupt one-carbon metabolism, and thus methyl group availability, leading to several developmental phenotypes (e.g., neural tube closure defects, fetal growth anomalies). Remarkably, previous studies showed that some of the phenotypes were transgenerationally inherited. Here, we explored the genome-wide epigenetic impact of one-carbon metabolism in placentas associated with fetal growth phenotypes and determined whether specific DNA methylation changes were inherited. Firstly, methylome analysis of Mtrr gt/gt homozygous placentas revealed genome-wide epigenetic instability. Several differentially methylated regions (DMRs) were identified including at the Cxcl1 gene promoter and at the En2 gene locus, which may have phenotypic implications. Importantly, we discovered hypomethylation and ectopic expression of a subset of ERV elements throughout the genome of Mtrr gt/gt placentas with broad implications for genomic stability. Next, we determined that known spermatozoan DMRs in Mtrr gt/gt males were reprogrammed in the placenta with little evidence of direct or transgenerational germline DMR inheritance. However, some spermatozoan DMRs were associated with placental gene misexpression despite normalisation of DNA methylation, suggesting the inheritance of an alternative epigenetic mechanism. Integration of published wildtype histone ChIP-seq datasets with Mtrr gt/gt spermatozoan methylome and placental transcriptome datasets point towards H3K4me3 deposition at key loci. These data suggest that histone modifications might play a role in epigenetic inheritance in this context. Overall, this study sheds light on the mechanistic complexities of one-carbon metabolism in development and epigenetic inheritance.

19.
Pediatr Blood Cancer ; : e30484, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37289143

RESUMO

BACKGROUND: Parents' views toward pediatric palliative care (PPC) remain underexplored, especially in low/middle-income countries where care relies heavily on families. A better understanding of parents' perspectives would inform strategies to support PPC integration into the care of children with cancer. This multicenter study aimed to examine knowledge, attitudes, and beliefs toward PPC among parents of children with cancer in Lebanon to uncover areas for improvement and determine associated factors. METHODS: Using a quantitative cross-sectional descriptive design, 105 primary caregivers (RR = 95.4%) were recruited during the child's visit to one of three pediatric oncology centers in Lebanon. Data were collected through structured interviews using questionnaire items newly developed or taken from validated tools. Data were analyzed using descriptive statistics, correlational analysis, and multiple linear regression. RESULTS: Only 18/105 participants (17.1%) had heard about PPC and 2% had accurate information about it. When given a brief description, more than 90% endorsed PPC and recommended its integration upon the child's diagnosis. Respectively, "Religious and spiritual engagement" and "Overwhelming negative emotions" were the most cited facilitators and barriers to integrating PPC. Knowledge, attitudes, and beliefs were significantly associated with several demographic and clinical factors such as education level, number of persons living with the child, child's symptom count, and pain score. CONCLUSION: This research is among the very first studies conducted to examine parents' perspectives toward PPC for children with cancer in Lebanon. Study findings inform future directions to promote PPC in limited-resource settings through expanded research, policy, education, and practice initiatives.

20.
Nat Struct Mol Biol ; 30(7): 935-947, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37308596

RESUMO

Mammalian genomes harbor abundant transposable elements (TEs) and their remnants, with numerous epigenetic repression mechanisms enacted to silence TE transcription. However, TEs are upregulated during early development, neuronal lineage, and cancers, although the epigenetic factors contributing to the transcription of TEs have yet to be fully elucidated. Here, we demonstrate that the male-specific lethal (MSL)-complex-mediated histone H4 acetylation at lysine 16 (H4K16ac) is enriched at TEs in human embryonic stem cells (hESCs) and cancer cells. This in turn activates transcription of subsets of full-length long interspersed nuclear elements (LINE1s, L1s) and endogenous retrovirus (ERV) long terminal repeats (LTRs). Furthermore, we show that the H4K16ac-marked L1 and LTR subfamilies display enhancer-like functions and are enriched in genomic locations with chromatin features associated with active enhancers. Importantly, such regions often reside at boundaries of topologically associated domains and loop with genes. CRISPR-based epigenetic perturbation and genetic deletion of L1s reveal that H4K16ac-marked L1s and LTRs regulate the expression of genes in cis. Overall, TEs enriched with H4K16ac contribute to the cis-regulatory landscape at specific genomic locations by maintaining an active chromatin landscape at TEs.


Assuntos
Elementos de DNA Transponíveis , Retrovirus Endógenos , Animais , Humanos , Masculino , Elementos de DNA Transponíveis/genética , Cromatina/genética , Sequências Reguladoras de Ácido Nucleico/genética , Retrovirus Endógenos/genética , Genômica , Mamíferos/genética
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