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1.
Nucleic Acids Res ; 52(W1): W126-W131, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38747349

RESUMO

Transposable elements (TEs) are abundant in the genomes of various eukaryote organisms. Increasing evidence suggests that TEs can play crucial regulatory roles-usually by creating cis-elements (e.g. enhancers and promoters) bound by distinct transcription factors (TFs). TE-derived cis-elements have gained unprecedented attentions recently, and one key step toward their understanding is to identify the enriched TEs in distinct genomic intervals (e.g. a set of enhancers or TF binding sites) as candidates for further study. Nevertheless, such analysis remains challenging for researchers unfamiliar with TEs or lack strong bioinformatic skills. Here, we present TEENA (Transposable Element ENrichment Analyzer) to streamline TE enrichment analysis in various organisms. It implements an optimized pipeline, hosts the genome/gene/TE annotations of almost one hundred species, and provides multiple parameters to enable its flexibility. Taking genomic interval data as the only user-supplied file, it can automatically retrieve the corresponding annotations and finish a routine analysis in a couple minutes. Multiple case studies demonstrate that it can produce highly reliable results matching previous knowledge. TEENA can be freely accessed at: https://sun-lab.yzu.edu.cn/TEENA. Due to its easy-to-use design, we expect it to facilitate the studies of the regulatory function of TEs in various model and non-model organisms.


Assuntos
Elementos de DNA Transponíveis , Internet , Software , Elementos de DNA Transponíveis/genética , Animais , Anotação de Sequência Molecular , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Humanos , Genômica/métodos
2.
Proc Natl Acad Sci U S A ; 119(22): e2120633119, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35605119

RESUMO

Dysregulated epigenetic and transcriptional programming due to abnormalities of transcription factors (TFs) contributes to and sustains the oncogenicity of cancer cells. Here, we unveiled the role of zinc finger protein 280C (ZNF280C), a known DNA damage response protein, as a tumorigenic TF in colorectal cancer (CRC), required for colitis-associated carcinogenesis and Apc deficiency­driven intestinal tumorigenesis in mice. Consistently, ZNF280C silencing in human CRC cells inhibited proliferation, clonogenicity, migration, xenograft growth, and liver metastasis. As a C2H2 (Cys2-His2) zinc finger-containing TF, ZNF280C occupied genomic intervals with both transcriptionally active and repressive states and coincided with CCCTC-binding factor (CTCF) and cohesin binding. Notably, ZNF280C was crucial for the repression program of trimethylation of histone H3 at lysine 27 (H3K27me3)-marked genes and the maintenance of both focal and broad H3K27me3 levels. Mechanistically, ZNF280C counteracted CTCF/cohesin activities and condensed the chromatin environment at the cis elements of certain tumor suppressor genes marked by H3K27me3, at least partially through recruiting the epigenetic repressor structural maintenance of chromosomes flexible hinge domain-containing 1 (SMCHD1). In clinical relevance, ZNF280C was highly expressed in primary CRCs and distant metastases, and a higher ZNF280C level independently predicted worse prognosis of CRC patients. Thus, our study uncovered a contributor with good prognostic value to CRC pathogenesis and also elucidated the essence of DNA-binding TFs in orchestrating the epigenetic programming of gene regulation.


Assuntos
Cromatina , Neoplasias Colorretais , Repressão Epigenética , Fator de Ligação a CCCTC/metabolismo , Carcinogênese/genética , Cromatina/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Proteínas de Ligação a DNA , Histonas/genética , Histonas/metabolismo , Humanos , Prognóstico , Fatores de Transcrição , Dedos de Zinco
3.
Carcinogenesis ; 45(8): 556-568, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-38756095

RESUMO

Cisplatin (DDP)-based combined chemotherapy or concurrent chemoradiotherapy is the mainstay treatment for advanced-stage nasopharyngeal carcinoma (NPC), but needs improvement due to its severe side effects. Capsaicin (CAP) can enhance the anti-tumor activity of cytotoxic drugs. The aim of this study was to investigate the anti-metastasis activity of CAP in combination with DDP in NPC. Herein, CAP and DDP showed synergistic cytotoxic effects on NPC cells. CAP alone and DDP alone inhibited NPC migration and invasion in vitro and in vivo, and the combination of CAP and DDP had the greatest effect. Moreover, CAP upregulated the mRNA and protein expressions of serpin family B member 2 (SERPINB2). Further results showed that both SERPINB2 mRNA and protein expressions were downregulated in NPC cell lines and tissues and SERPINB2 overexpression inhibited NPC migration and invasion in vitro and in vivo, while silencing SERPINB2 acted oppositely. In addition, SERPINB2 was abnormally expressed in head and neck squamous cell carcinoma and other multiple cancers, and downregulation of SERPINB2 predicted poor prognosis in head and neck squamous cell carcinoma according to the Cancer Genome Atlas database. We further found that SERPINB2 overexpression inhibited epithelial-mesenchymal transition (EMT) and the phosphorylated extracellular signal-regulated kinase (p-ERK), and the inhibitory effect was enhanced by CAP and DDP. Altogether, our results suggest that the combined inhibition of CAP and DDP on NPC metastasis may be related to the inhibition of epithelial-mesenchymal transition and ERK signals mediated by SERPINB2, and CAP may help to improve the efficacy of DDP in the treatment of NPC and develop new therapeutic approaches.


Assuntos
Capsaicina , Movimento Celular , Cisplatino , Transição Epitelial-Mesenquimal , Sistema de Sinalização das MAP Quinases , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Inibidor 2 de Ativador de Plasminogênio , Humanos , Cisplatino/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/metabolismo , Carcinoma Nasofaríngeo/genética , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Animais , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/genética , Camundongos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Inibidor 2 de Ativador de Plasminogênio/metabolismo , Inibidor 2 de Ativador de Plasminogênio/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proliferação de Células/efeitos dos fármacos , Camundongos Nus , Sinergismo Farmacológico , Feminino , Camundongos Endogâmicos BALB C
4.
Small ; 20(14): e2309272, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988706

RESUMO

Despite incorporation of organic groups into silica-based aerogels to enhance their mechanical flexibility, the wide temperature reliability of the modified silicone aerogel is inevitably degraded. Therefore, facile synthesis of soft silicone aerogels with wide-temperature stability remains challenging. Herein, novel silicone aerogels containing a high content of Si are reported by using polydimethylvinylsiloxane (PDMVS), a hydrosilylation adduct with water-repellent groups, as a "flexible chain segment" embedded within the aerogel network. The poly(2-dimethoxymethylsilyl)ethylmethylvinylsiloxane (PDEMSEMVS) aerogel is fabricated through a cost-effective ambient temperature/pressure drying process. The optimized aerogel exhibits exceptional performance, such as ultra-low density (50 mg cm-3), wide-temperature mechanical flexibility, and super-hydrophobicity, in comparison to the previous polysiloxane aerogels. A significant reduction in the density of these aerogels is achieved while maintaining a high crosslinking density by synthesizing gel networks with well-defined macromolecules through hydrolytic polycondensation crosslinking of PDEMSEMVS. Notably, the pore/nanoparticle size of aerogels can be fine-tuned by optimizing the gel solvent type. The as-prepared silicone aerogels demonstrate selective absorption, efficient oil-water separation, and excellent thermal insulation properties, showing promising applications in oil/water separation and thermal protection.

5.
J Aging Phys Act ; 31(6): 948-955, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37263592

RESUMO

This prospective study aimed to determine which specific mobility tests were the most accurate for predicting falls in physically active older adults living in the community. Seventy-nine physically active older adults who met the American College of Sports Medicine physical activity guidelines volunteered. Participants were assessed and followed up for 12 months. Mobility assessments included the 30-s sit-to-stand test, five times sit-to-stand test, single-task timed-up-and-go test (TUG), motor dual-task TUG (Mot-TUG), and cognitive dual-task TUG (Cog-TUG). Mot-TUG and Cog-TUG performances were moderately correlated with number of falls (r = .359, p < .01 and r = .372, p < .01, respectively). When Mot-TUG, Cog-TUG, or Age were included as fall predictors, discrimination scores represented by the area under the receiver operating characteristic curve (AUC) were AUC (Mot-TUG) = 0.843 (p < .01), AUC (Cog-TUG) = 0.856 (p < .01), and AUC (Age) = 0.734 (p < .05). The cutoff point for Cog-TUG was 10.98 s, with test sensitivity of 1.00 and specificity of 0.66. Fall predictors for different populations may be based on different test methods. Here, the dual-task TUG test more accurately predicted falls in older adults who met American College of Sports Medicine's physical activity guidelines.


Assuntos
Vida Independente , Equilíbrio Postural , Humanos , Idoso , Estudos Prospectivos , Avaliação Geriátrica/métodos , Estudos de Tempo e Movimento
6.
Mol Biol Evol ; 38(11): 4992-5004, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34320657

RESUMO

In mammals, the placenta mediates maternal-fetal nutrient and waste exchange and acts in an immunomodulatory way to facilitate maternal-fetal tolerance. The placenta is highly diverse across mammalian species, yet the molecular mechanisms that distinguish the placenta of human from other mammals are not fully understood. Using an interspecies transcriptomic comparison of human, macaque, and mouse late-gestation placentae, we identified hundreds of genes with lineage-specific expression-including dozens that are placentally enriched and potentially related to pregnancy. We further annotated the enhancers for different human tissues using epigenomic data and demonstrate that the placenta and chorion are unique in that their enhancers display the least conservation. We identified numerous lineage-specific human placental enhancers and found they highly overlap with specific families of endogenous retroviruses (ERVs), including MER21A, MER41A/B, and MER39B that were previously linked to immune response and placental function. Among these ERV families, we further demonstrate that MER41A/B insertions create dozens of lineage-specific serum response factor-binding loci in human, including one adjacent to FBN2, a placenta-specific gene with increased expression in humans that produces the peptide hormone placensin to stimulate glucose secretion and trophoblast invasion. Overall, our results demonstrate the prevalence of lineage-specific placental enhancers which are frequently associated with ERV insertions and likely facilitate the lineage-specific evolution of the mammalian placenta.


Assuntos
Retrovirus Endógenos , Animais , Retrovirus Endógenos/genética , Feminino , Camundongos , Placenta/metabolismo , Gravidez , Primatas/genética , Roedores/genética , Trofoblastos
7.
Appl Environ Microbiol ; 88(7): e0006022, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35285711

RESUMO

Bacterial porin-encoding genes are often found under positive selection. Local recombination has also been identified in a few of them to facilitate bacterial rapid adaptation, although it remains unknown whether it is a common evolutionary mechanism for the porins or outer membrane proteins in Gram-negative bacteria. In this study, we investigated the beta-barrel (ß-barrel) porin-encoding genes in Escherichia coli that were reported under positive Darwinian selection. Besides fhuA that was found with ingenic local recombination previously, we identified four other genes, i.e., lamB, ompA, ompC, and ompF, all showing the similar mosaic evolution patterns. Comparative analysis of the protein sequences disclosed a list of highly variable regions in each family, which are mostly located in the convex of extracellular loops and coinciding with the binding sites of bacteriophages. For each of the porin families, mosaic recombination leads to unique combinations of the variable regions with different sequence patterns, generating diverse protein groups. Structural modeling indicated a conserved global topology among the different porins, with the extracellular surface varying a lot due to individual or combinatorial variable regions. The conservation of global tertiary structure would ensure the channel activity, while the wide diversity of variable regions may represent selection to avoid the invasion of phages, antibiotics or immune surveillance factors. Our study identified multiple bacterial porin genes with mosaic evolution. We hypothesize that this could be generalized strategy for outer membrane proteins to both maintain normal life processes and evade the attack of unfavored factors rapidly. IMPORTANCE Microevolution studies can disclose more elaborate evolutionary mechanisms of genes, appearing especially important for genes with multifaceted function such as those encoding outer membrane proteins. However, in most cases, the gene is considered as a whole unit, and the evolutionary patterns are disclosed. Here, we report that multiple bacterial porin proteins follow mosaic evolution, with local ingenic recombination combined with spontaneous mutations based on positive Darwinian selection, and conservation for most structural regions. This could represent a common mechanism for bacterial outer membrane proteins. The variable regions within each porin family showed large coincidence with the binding sites of bacteriophages, antibiotics, and immune factors and therefore would represent effective targets for the development of new antibacterial agents or vaccines.


Assuntos
Escherichia coli , Porinas , Animais , Antibacterianos/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Porinas/genética , Porinas/metabolismo , Ovinos
8.
Plant Cell ; 31(12): 2888-2911, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31628162

RESUMO

Modern wheat production comes from two polyploid species, Triticum aestivum and Triticum turgidum (var durum), which putatively arose from diploid ancestors Triticum urartu, Aegilops speltoides, and Aegilops tauschii How gene expression during embryogenesis and grain development in wheats has been shaped by the differing contributions of diploid genomes through hybridization, polyploidization, and breeding selection is not well understood. This study describes the global landscape of gene activities during wheat embryogenesis and grain development. Using comprehensive transcriptomic analyses of two wheat cultivars and three diploid grasses, we investigated gene expression at seven stages of embryo development, two endosperm stages, and one pericarp stage. We identified transcriptional signatures and developmental similarities and differences among the five species, revealing the evolutionary divergence of gene expression programs and the contributions of A, B, and D subgenomes to grain development in polyploid wheats. The characterization of embryonic transcriptional programming in hexaploid wheat, tetraploid wheat, and diploid grass species provides insight into the landscape of gene expression in modern wheat and its ancestral species. This study presents a framework for understanding the evolution of domesticated wheat and the selective pressures placed on grain production, with important implications for future performance and yield improvements.plantcell;31/12/2888/FX1F1fx1.


Assuntos
Grão Comestível/crescimento & desenvolvimento , Transcriptoma/genética , Triticum/genética , Análise por Conglomerados , Diploide , Grão Comestível/genética , Endosperma/genética , Endosperma/metabolismo , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta , Poliploidia , Sementes/genética , Sementes/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma/fisiologia , Triticum/embriologia
9.
PLoS Genet ; 15(6): e1008233, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31233504

RESUMO

Pathogenic Salmonella strains that cause gastroenteritis are able to colonize and replicate within the intestines of multiple host species. In general, these strains have retained an ability to form the rdar morphotype, a resistant biofilm physiology hypothesized to be important for Salmonella transmission. In contrast, Salmonella strains that are host-adapted or even host-restricted like Salmonella enterica serovar Typhi, tend to cause systemic infections and have lost the ability to form the rdar morphotype. Here, we investigated the rdar morphotype and CsgD-regulated biofilm formation in two non-typhoidal Salmonella (NTS) strains that caused invasive disease in Malawian children, S. Typhimurium D23580 and S. Enteritidis D7795, and compared them to a panel of NTS strains associated with gastroenteritis, as well as S. Typhi strains. Sequence comparisons combined with luciferase reporter technology identified key SNPs in the promoter region of csgD that either shut off biofilm formation completely (D7795) or reduced transcription of this key biofilm regulator (D23580). Phylogenetic analysis showed that these SNPs are conserved throughout the African clades of invasive isolates, dating as far back as 80 years ago. S. Typhi isolates were negative for the rdar morphotype due to truncation of eight amino acids from the C-terminus of CsgD. We present new evidence in support of parallel evolution between lineages of nontyphoidal Salmonella associated with invasive disease in Africa and the archetypal host-restricted invasive serovar; S. Typhi. We hypothesize that the African invasive isolates are becoming human-adapted and 'niche specialized' with less reliance on environmental survival, as compared to gastroenteritis-causing isolates.


Assuntos
Evolução Biológica , Gastroenterite/genética , Infecções por Salmonella/genética , Salmonella typhimurium/genética , África/epidemiologia , Biofilmes/crescimento & desenvolvimento , Criança , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella typhimurium/patogenicidade , Transativadores/genética
10.
Int J Mol Sci ; 23(18)2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36142130

RESUMO

Stably Expressed Genes (SEGs) are a set of genes with invariant expression. Identification of SEGs, especially among both healthy and diseased tissues, is of clinical relevance to enable more accurate data integration, gene expression comparison and biomarker detection. However, it remains unclear how many global SEGs there are, whether there are development-, tissue- or cell-specific SEGs, and whether diseases can influence their expression. In this research, we systematically investigate human SEGs at single-cell level and observe their development-, tissue- and cell-specificity, and expression stability under various diseased states. A hierarchical strategy is proposed to identify a list of 408 spatial-temporal SEGs. Development-specific SEGs are also identified, with adult tissue-specific SEGs enriched with the function of immune processes and fetal tissue-specific SEGs enriched in RNA splicing activities. Cells of the same type within different tissues tend to show similar SEG composition profiles. Diseases or stresses do not show influence on the expression stableness of SEGs in various tissues. In addition to serving as markers and internal references for data normalization and integration, we examine another possible application of SEGs, i.e., being applied for cell decomposition. The deconvolution model could accurately predict the fractions of major immune cells in multiple independent testing datasets of peripheral blood samples. The study provides a reliable list of human SEGs at the single-cell level, facilitates the understanding on the property of SEGs, and extends their possible applications.

11.
Carcinogenesis ; 42(1): 80-92, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32459848

RESUMO

OBJECTIVES: Increasing evidence suggest that long non-coding RNAs (lncRNAs) play critical roles in cancers. However, the expression pattern and underlying mechanisms of lncRNAs in non-small cell lung cancer (NSCLC) remain incompletely understood. This study aimed to elucidate the functions and molecular mechanisms of a certain lncRNA in NSCLC. METHODS: LncRNA microarray was performed to identify differential expressed lncRNAs between pre- and postoperation plasma in NSCLC patients. The expression level of candidate lncRNA in NSCLC tissues, plasma and cells was determined by quantitative real-time PCR (qRT-PCR) and in situ hybridization. The functional roles of lncRNA were assessed in vitro and in vivo. Furthermore, RNA pull-down, RNA immunoprecipitation, microarray, qRT-PCR and rescue assays were conducted to explore the mechanism action of lncRNA in NSCLC cells. RESULTS: We identified a novel lncRNA (BRCAT54), which was significantly upregulated in preoperative plasma, NSCLC tissues and NSCLC cells, and its higher expression was associated with better prognosis in patients with NSCLC. Overexpression of BRCAT54 inhibited proliferation, migration and activated apoptosis in NSCLC cells. Conversely, knockdown of BRCAT54 reversed the suppressive effects of BRCAT54. Moreover, overexpression of BRCAT54 repressed NSCLC cell growth in vivo. Mechanistically, BRCAT54 directly bound to RPS9. Knockdown of RPS9 substantially reversed the promoting effects of si-BRCAT54 on cell proliferation and enhanced the inhibitive effect of si-BRCAT54 on BRCAT54 expression. In addition, silencing of RPS9 activated JAK-STAT pathway and suppressed calcium signaling pathway gene expressions. CONCLUSION: This study identified BRCAT54 as a tumor suppressor in NSCLC. Targeting the BRCAT54 and RPS9 feedback loop might be a novel therapeutic strategy for NSCLC.


Assuntos
Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , RNA Longo não Codificante/metabolismo , Proteínas Ribossômicas/genética , Adulto , Idoso , Animais , Sinalização do Cálcio/genética , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Linhagem Celular Tumoral , Proliferação de Células/genética , Retroalimentação Fisiológica , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Genes Supressores de Tumor , Humanos , Janus Quinases/metabolismo , Pulmão/patologia , Pulmão/cirurgia , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/cirurgia , Masculino , Camundongos , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Pneumonectomia , Prognóstico , RNA Longo não Codificante/sangue , RNA Longo não Codificante/genética , Proteína S9 Ribossômica , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/genética , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Infect Immun ; 89(4)2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33468583

RESUMO

Nontyphoidal Salmonella (NTS) strains are associated with gastroenteritis worldwide but are also the leading cause of bacterial bloodstream infections in sub-Saharan Africa. The invasive NTS (iNTS) strains that cause bloodstream infections differ from standard gastroenteritis-causing strains by >700 single-nucleotide polymorphisms (SNPs). These SNPs are known to alter metabolic pathways and biofilm formation and to contribute to serum resistance and are thought to signify iNTS strains becoming human adapted, similar to typhoid fever-causing Salmonella strains. Identifying SNPs that contribute to invasion or increased virulence has been more elusive. In this study, we identified a SNP in the cache 1 signaling domain of diguanylate cyclase STM1987 in the invasive Salmonella enterica serovar Typhimurium type strain D23580. This SNP was conserved in 118 other iNTS strains analyzed and was comparatively absent in global S Typhimurium isolates associated with gastroenteritis. STM1987 catalyzes the formation of bis-(3',5')-cyclic dimeric GMP (c-di-GMP) and is proposed to stimulate production of cellulose independent of the master biofilm regulator CsgD. We show that the amino acid change in STM1987 leads to a 10-fold drop in cellulose production and increased fitness in a mouse model of acute infection. Reduced cellulose production due to the SNP led to enhanced survival in both murine and human macrophage cell lines. In contrast, loss of CsgD-dependent cellulose production did not lead to any measurable change in in vivo fitness. We hypothesize that the SNP in stm1987 represents a pathoadaptive mutation for iNTS strains.


Assuntos
Proteínas de Bactérias/genética , Aptidão Genética , Polimorfismo de Nucleotídeo Único , Domínios e Motivos de Interação entre Proteínas , Infecções por Salmonella/microbiologia , Salmonella/genética , Animais , Proteínas de Bactérias/metabolismo , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Viabilidade Microbiana , Salmonella/metabolismo , Salmonella typhimurium/genética , Salmonella typhimurium/patogenicidade , Virulência/genética
13.
Proc Natl Acad Sci U S A ; 115(21): E4741-E4750, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29735717

RESUMO

Cells in tissues undergo transdifferentiation programs when stimulated by specific mechanical and biochemical signals. While seminal studies have demonstrated that exogenous biochemical factors can reprogram somatic cells into pluripotent stem cells, the critical roles played by mechanical signals in such reprogramming process have not been well documented. In this paper, we show that laterally confined growth of fibroblasts on micropatterned substrates induces nuclear reprogramming with high efficiency in the absence of any exogenous reprogramming factors. We provide compelling evidence on the induction of stem cell-like properties using alkaline phosphatase assays and expression of pluripotent markers. Early onset of reprogramming was accompanied with enhanced nuclear dynamics and changes in chromosome intermingling degrees, potentially facilitating rewiring of the genome. Time-lapse analysis of promoter occupancy by immunoprecipitation of H3K9Ac chromatin fragments revealed that epithelial, proliferative, and reprogramming gene promoters were progressively acetylated, while mesenchymal promoters were deacetylated by 10 days. Consistently, RNA sequencing analysis showed a systematic progression from mesenchymal to stem cell transcriptome, highlighting pathways involving mechanisms underlying nuclear reprogramming. We then demonstrated that these mechanically reprogrammed cells could be maintained as stem cells and can be redifferentiated into multiple lineages with high efficiency. Importantly, we also demonstrate the induction of cancer stemness properties in MCF7 cells grown in such laterally confined conditions. Collectively, our results highlight an important generic property of somatic cells that, when grown in laterally confined conditions, acquire stemness. Such mechanical reprogramming of somatic cells demonstrated here has important implications in tissue regeneration and disease models.


Assuntos
Neoplasias da Mama/genética , Linhagem da Célula , Reprogramação Celular , Cromatina/genética , Células-Tronco Pluripotentes Induzidas/citologia , Transcriptoma , Animais , Transdiferenciação Celular , Epigênese Genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Células-Tronco Pluripotentes Induzidas/fisiologia , Camundongos , Células NIH 3T3 , Células Tumorais Cultivadas
14.
Opt Lett ; 45(17): 4690-4693, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32870833

RESUMO

Ultra-short optical pulses in the ultraviolet (UV) region are of significant interest for combustion and reacting flow diagnostics, as most important chemical species have electronic resonance transitions in the UV region. Optical parametric amplifiers are typically used for frequency conversion of femtosecond (fs) pulses from near-IR to UV; however, their implementation for practical imaging applications is limited because of the low conversion efficiency and extreme sensitivity to ambient conditions. In this work, we report the implementation of direct-frequency-tripled, fs laser pulses from a tunable amplified laser system for high-resolution imaging of hydroxyl (OH) radical in flames. The fundamental laser output near 850 nm is frequency tripled to obtain approximately 283.3-nm UV radiation. OH planar laser-induced fluorescence (PLIF) imaging at 1 kHz is demonstrated in turbulent flames with image sheet heights in excess of 45 mm and a signal-to-noise ratio better than 25. These results represent over 3× increase in the imaging dimensionality compared to traditional OPA-based systems. Additionally, the third-harmonic generation apparatus is compact, robust, and easy to operate while providing near-Gaussian beam profiles. Simple power scaling suggests another factor of 3 or more increase in sheet height can be achieved for kilohertz-rate practical combustion diagnostics applications.

15.
Proc Natl Acad Sci U S A ; 114(20): E3882-E3891, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28461498

RESUMO

Cells in physiology integrate local soluble and mechanical signals to regulate genomic programs. Whereas the individual roles of these signals are well studied, the cellular responses to the combined chemical and physical signals are less explored. Here, we investigated the cross-talk between cellular geometry and TNFα signaling. We stabilized NIH 3T3 fibroblasts into rectangular anisotropic or circular isotropic geometries and stimulated them with TNFα and analyzed nuclear translocation of transcription regulators -NFκB (p65) and MKL and downstream gene-expression patterns. We found that TNFα induces geometry-dependent actin depolymerization, which enhances IκB degradation, p65 nuclear translocation, nuclear exit of MKL, and sequestration of p65 at the RNA-polymerase-II foci. Further, global transcription profile of cells under matrix-TNFα interplay reveals a geometry-dependent gene-expression pattern. At a functional level, we find cell geometry affects TNFα-induced cell proliferation. Our results provide compelling evidence that fibroblasts, depending on their geometries, elicit distinct cellular responses for the same cytokine.


Assuntos
Expressão Gênica/fisiologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Animais , Núcleo Celular/metabolismo , Forma Celular/genética , Tamanho Celular , Fibroblastos/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas I-kappa B/metabolismo , Camundongos , Células NIH 3T3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transativadores/metabolismo , Fator de Transcrição RelA/metabolismo
16.
Opt Lett ; 44(24): 5945-5948, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32628192

RESUMO

In many recent studies, ultrashort femtosecond (fs) two-photon (2p) laser-induced fluorescence (LIF) of atomic hydrogen (H) has been demonstrated using a 205 nm excitation. However, 205-nm- deep ultraviolet (UV) pulses can be problematic in practical devices containing thick transmissive optics and can also be susceptible to photolytic production at high laser energies. In this Letter, we investigate the three-photon (3p) excitation scheme of H by using red-shifted 307.7 nm fs laser pulses. Efficient 3p excitation resulting from fs laser pulses enable the 3pLIF detection of H, which was previously unattainable in most flame conditions using ns or ps pulses. Measurements are reported in CH4/O2/N2 Bunsen jet flames and premixed CH4/air flames and compared to similar 2pLIF schemes with fs pulses. Saturation effects, photolytic interferences, and stimulated emissions effects are studied, as well as the benefits of 3pLIF in diagnostic hardware with thick optical windows.

17.
BMC Cancer ; 19(1): 263, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30902072

RESUMO

BACKGROUND: Lung adenocarcinoma is the most common type of lung cancers. Whole-genome sequencing studies disclosed the genomic landscape of lung adenocarcinomas. however, it remains unclear if the genetic alternations could guide prognosis prediction. Effective genetic markers and their based prediction models are also at a lack for prognosis evaluation. METHODS: We obtained the somatic mutation data and clinical data for 371 lung adenocarcinoma cases from The Cancer Genome Atlas. The cases were classified into two prognostic groups (3-year survival), and a comparison was performed between the groups for the somatic mutation frequencies of genes, followed by development of computational models to discrete the different prognosis. RESULTS: Genes were found with higher mutation rates in good (≥ 3-year survival) than in poor (< 3-year survival) prognosis group of lung adenocarcinoma patients. Genes participating in cell-cell adhesion and motility were significantly enriched in the top gene list with mutation rate difference between the good and poor prognosis group. Support Vector Machine models with the gene somatic mutation features could well predict prognosis, and the performance improved as feature size increased. An 85-gene model reached an average cross-validated accuracy of 81% and an Area Under the Curve (AUC) of 0.896 for the Receiver Operating Characteristic (ROC) curves. The model also exhibited good inter-stage prognosis prediction performance, with an average AUC of 0.846 for the ROC curves. CONCLUSION: The prognosis of lung adenocarcinomas is related with somatic gene mutations. The genetic markers could be used for prognosis prediction and furthermore provide guidance for personal medicine.


Assuntos
Adenocarcinoma de Pulmão/mortalidade , Biomarcadores Tumorais/genética , Neoplasias Pulmonares/mortalidade , Modelos Biológicos , Máquina de Vetores de Suporte , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/terapia , Biologia Computacional , Conjuntos de Dados como Assunto , Estudos de Viabilidade , Genômica/métodos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Mutação , Medicina de Precisão/métodos , Prognóstico , Curva ROC , Análise de Sobrevida , Taxa de Sobrevida
18.
J Pathol ; 244(1): 36-48, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28940253

RESUMO

It has long been known that patients suffering from inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). The innate immune system of host cells provides a first-line defence against pathogenic infection, whereas an uncontrolled inflammatory response under homeostatic conditions usually leads to pathological consequences, as exemplified by the chronic inflammation of IBD. The key molecules and pathways keeping innate immunity in check are still poorly defined. Here, we report that the chromatin remodeller polybromo-1 (PBRM1) is a repressor of innate immune signalling mediated by retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs). Knockdown of PBRM1 in colon cancer cells increased the expression of two receptor genes (RIG-I and MDA5) and upregulated interferon (IFN)-related and inflammation-related gene signatures. The innate immune signal stimulated by a double-stranded RNA viral mimic was exaggerated by PBRM1 suppression. PBRM1 cooperated with polycomb protein EZH2 to directly bind the cis-regulatory elements of RIG-I and MDA5, thereby suppressing their transcription. Moreover, upregulation of RIG-I and MDA5 is required for IFN response activation induced by PBRM1 silencing. TRIM25, a protein stimulated by the RLR pathway and IFN production, physically interacted with PBRM1 and induced PBRM1 protein destabilization by promoting its ubiquitination. These findings reveal a PBRM1-RLR regulatory circuit that can keep innate immune activity at a minimal level in resting cells, and also ensure a robust inflammatory response in the case of pathogen invasion. PBRM1 was found to be downregulated in primary tissues from patients with CRC or IBD, and its expression correlated negatively with that of RLR genes and interferon-stimulated genes in CRC samples. Lower PBRM1 expression was associated with advanced pathological grade and poorer survival of CRC patients, indicating that PBRM1 could serve as a potential prognostic biomarker for CRC. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Neoplasias do Colo/genética , Epigenômica , Imunidade Inata , Doenças Inflamatórias Intestinais/complicações , Proteínas Nucleares/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Idoso , Biomarcadores/metabolismo , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Proteína DEAD-box 58/genética , Proteína DEAD-box 58/metabolismo , Proteínas de Ligação a DNA , Feminino , Humanos , Doenças Inflamatórias Intestinais/imunologia , Helicase IFIH1 Induzida por Interferon/genética , Helicase IFIH1 Induzida por Interferon/metabolismo , Masculino , Proteínas Nucleares/genética , Prognóstico , RNA Interferente Pequeno , Receptores Imunológicos , Análise de Sequência de RNA , Fatores de Transcrição/genética , Tretinoína/metabolismo , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
19.
Appl Opt ; 58(10): C23-C29, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045027

RESUMO

Extension of laser diagnostic methods to high pressure is critically important because most practical combustion systems operate at elevated pressures. However, increased collisional quenching, fluorescence trapping, and other spectroscopic complications make high-pressure laser diagnostics extremely challenging. As the pressure increases, collisional effects broaden and shift excitation spectral lines, reducing the excitation quantum efficiency of the laser-induced fluorescence (LIF) technique, in particular when using conventional narrowband, nanosecond (ns)-duration laser pulses. In this work, spectroscopic investigation of broadband, femtosecond two-photon LIF (fs-TPLIF) of carbon monoxide (CO) was performed in a high-pressure static gas cell, up to total pressures of 20 bar. The fluorescence emission spectrum broadened marginally at the highest pressure investigated and hence can be neglected in most cases. The subquadratic dependence of the CO fs-TPLIF signal on the laser fluence increased as the pressure is increased. Moreover, the CO fs-TPLIF signal decays more slowly with increasing pressure compared to the previously reported ns-TPLIF data. The signal drop when the total pressure is increased from 1 to 13 bar is approximately 30% in the fs excitation, as compared to approximately a 60% drop in the ns excitation in CO/N2/O2 mixtures. The pressure effects on the fluorescence signal were observed to be similar in the Ångström and third positive bands, suggesting that the third positive band could also be used for CO measurements with broadband fs laser pulses. Furthermore, experimentally investigated are the effect of pressure on the CO fluorescence signal in different quenching gases using fixed CO mole fractions, as well as number densities. Overall, the fs-TPLIF scheme is shown to be a promising diagnostics tool for CO detection in practical combustion systems at elevated pressures.

20.
Infect Immun ; 86(11)2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30150258

RESUMO

The fhuACDB operon, present in a number of Enterobacteriaceae, encodes components essential for the uptake of ferric hydroxamate type siderophores. FhuA acts not only as a transporter for physiologically important chelated ferric iron but also as a receptor for various bacteriophages, toxins, and antibiotics, which are pathogenic to bacterial cells. In this research, fhuA gene distribution and sequence diversity were investigated in Enterobacteriaceae, especially Salmonella and Escherichia Comparative sequence analysis resulted in a fhuA phylogenetic tree that did not match the expected phylogeny of species or trees of the fhuCDB genes. The fhuA sequences showed a unique mosaic clustering pattern. On the other hand, the gene sequences showed high conservation for strains from the same serovar or serotype. In total, six clusters were identified from FhuA proteins in Salmonella and Escherichia, among which typical peptide fragment variations could be defined. Six fragmental insertions/deletions and two substitution fragments were discovered, for which the combination of polymorphism patterns could well classify the different clusters. Structural modeling demonstrated that all the six featured insertions/deletions and one substitution fragment are located at the apexes of the long loops present as part of the FhuA external pocket. These frequently mutated regions are likely under high selection pressure, with bacterial strains balancing escape from phage infection or toxin/antibiotics attack via fhuA gene mutations while maintaining the siderophore uptake activity essential for bacterial survival. The unusual fhuA clustering suggests that high-frequency exchange of fhuA genes has occurred between enterobacterial strains after distinctive species were established.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Escherichia coli/genética , Escherichia/genética , Evolução Molecular , Variação Genética , Salmonella/genética , Proteínas da Membrana Bacteriana Externa/química , Análise por Conglomerados , Proteínas de Escherichia coli/química , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/genética , Modelos Moleculares , Filogenia , Receptores Virais/química , Receptores Virais/genética , Análise de Sequência de DNA , Homologia de Sequência
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