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2.
Front Oncol ; 14: 1227151, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756663

RESUMO

Stress-induced promoter-associated and antisense lncRNAs (si-paancRNAs) originate from a reservoir of oxidative stress (OS)-specific promoters via RNAPII pausing-mediated divergent antisense transcription. Several studies have shown that the KDM7A divergent transcript gene (KDM7A-DT), which encodes a si-paancRNA, is overexpressed in some cancer types. However, the mechanisms of this overexpression and its corresponding roles in oncogenesis and cancer progression are poorly understood. We found that KDM7A-DT expression is correlated with highly aggressive cancer types and specific inherently determined subtypes (such as ductal invasive breast carcinoma (BRCA) basal subtype). Its regulation is determined by missense TP53 mutations in a subtype-specific context. KDM7A-DT transcribes several intermediate-sized ncRNAs and a full-length transcript, exhibiting distinct expression and localization patterns. Overexpression of KDM7A-DT upregulates TP53 protein expression and H2AX phosphorylation in nonmalignant fibroblasts, while in semi-transformed fibroblasts, OS superinduces KDM7A-DT expression in a TP53-dependent manner. KDM7A-DT knockdown and gene expression profiling in TP53-missense mutated luminal A BRCA variant, where it is abundantly expressed, indicate its significant role in cancer pathways. Endogenous over-expression of KDM7A-DT inhibits DNA damage response/repair (DDR/R) via the TP53BP1-mediated pathway, reducing apoptosis and promoting G2/M checkpoint arrest. Higher KDM7A-DT expression in BRCA is associated with KDM7A-DT locus gain/amplification, higher histologic grade, aneuploidy, hypoxia, immune modulation scores, and activation of the c-myc pathway. Higher KDM7A-DT expression is associated with relatively poor survival outcomes in patients with luminal A or Basal subtypes. In contrast, it is associated with favorable outcomes in patients with HER2+ER- or luminal B subtypes. KDM7A-DT levels are coregulated with critical transcripts and proteins aberrantly expressed in BRCA, including those involved in DNA repair via non-homologous end joining and epithelial-to-mesenchymal transition pathway. In summary, KDM7A-DT and its si-lncRNA exhibit several intrinsic biological and clinical characteristics that suggest important roles in invasive BRCA and its subtypes. KDM7A-DT-defined mRNA and protein subnetworks offer resources for identifying clinically relevant RNA-based signatures and prospective targets for therapeutic intervention.

3.
Data Brief ; 50: 109550, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37743888

RESUMO

When several continuous guanine runs are present closely in a nucleic acid sequence, a secondary structure called G-quadruplex can form (G4s). Such structures in the genome could serve as structural and functional regulators in gene expression, DNA-protein binding, epigenetic modification, and genotoxic stress. Several types of G4-forming DNA sequences exist, including bulged G4-forming sequences (G4-BS). Such bulges occur due to the presence of non-guanine bases in specific locations (G-runs) in the G4-forming sequences. At present, search algorithms do not identify stable G4-BS conformations, making genome-wide studies of G4-like structures difficult. Data provided in this study are related to a published article "Stable bulged G-quadruplexes in the human genome: Identification, experimental validation and functionalization" published by Nucleic Acids Research [DIO.org/10.193/nar/gkad252]. Based on our studies in vitro and G4-seq and G4 CUT&Tag data analysis, we have specified and validated three pG4-BS models. In this article, a large collection of 'raw' (unfiltered) dataset is presented, which includes three subfamilies of pG4-BS. For each of pG4-BS, we provide strand-specific genomic boundaries. Data on pG4-BS might be useful in elucidating their structural, functional, and evolutionary roles. Furthermore, they may provide insight into the pathobiology of G4-like structures and their potential therapeutic applications.

4.
Nucleic Acids Res ; 51(9): 4148-4177, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37094040

RESUMO

DNA sequence composition determines the topology and stability of G-quadruplexes (G4s). Bulged G-quadruplex structures (G4-Bs) are a subset of G4s characterized by 3D conformations with bulges. Current search algorithms fail to capture stable G4-B, making their genome-wide study infeasible. Here, we introduced a large family of computationally defined and experimentally verified potential G4-B forming sequences (pG4-BS). We found 478 263 pG4-BS regions that do not overlap 'canonical' G4-forming sequences in the human genome and are preferentially localized in transcription regulatory regions including R-loops and open chromatin. Over 90% of protein-coding genes contain pG4-BS in their promoter or gene body. We observed generally higher pG4-BS content in R-loops and their flanks, longer genes that are associated with brain tissue, immune and developmental processes. Also, the presence of pG4-BS on both template and non-template strands in promoters is associated with oncogenesis, cardiovascular disease and stemness. Our G4-BS models predicted G4-forming ability in vitro with 91.5% accuracy. Analysis of G4-seq and CUT&Tag data strongly supports the existence of G4-BS conformations genome-wide. We reconstructed a novel G4-B 3D structure located in the E2F8 promoter. This study defines a large family of G4-like sequences, offering new insights into the essential biological functions and potential future therapeutic uses of G4-B.


Assuntos
Quadruplex G , Humanos , Genoma Humano/genética , Estudo de Associação Genômica Ampla , Regiões Promotoras Genéticas , Sequência de Bases
5.
Genes (Basel) ; 13(7)2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35886011

RESUMO

Cancer genomes are characterized by the accumulation of small-scale somatic mutations as well as large-scale chromosomal deletions, amplifications, and complex structural rearrangements. This characteristic is at least partially dependent on the ability of cancer cells to undergo recurrent chromosome breakage. In order to address the extent to which chromosomal structural rearrangement breakpoints correlate with recurrent DNA double-strand breaks (DSBs), we simultaneously mapped chromosome structural variation breakpoints (using whole-genome DNA-seq) and spontaneous DSB formation (using Break-seq) in the estrogen receptor (ER)-positive breast cancer cell line MCF-7 and a non-cancer control breast epithelium cell line MCF-10A. We identified concurrent DSBs and structural variation breakpoints almost exclusively in the pericentromeric region of chromosome 16q in MCF-7 cells. We fine-tuned the identification of copy number variation breakpoints on 16q. In addition, we detected recurrent DSBs that occurred in both MCF-7 and MCF-10A. We propose a model for DSB-driven chromosome rearrangements that lead to the translocation of 16q, likely with 10q, and the eventual 16q loss that does not involve the pericentromere of 16q. We present evidence from RNA-seq data that select genes, including SHCBP1, ORC6, and MYLK3, which are immediately downstream from the 16q pericentromere, show heightened expression in MCF-7 cell line compared to the control. Data published by The Cancer Genome Atlas show that all three genes have increased expression in breast tumor samples. We found that SHCBP1 and ORC6 are both strong poor prognosis and treatment outcome markers in the ER-positive breast cancer cohort. We suggest that these genes are potential oncogenes for breast cancer progression. The search for tumor suppressor loss that accompanies the 16q loss ought to be augmented by the identification of potential oncogenes that gained expression during chromosomal rearrangements.


Assuntos
Neoplasias da Mama , Quebra Cromossômica , Neoplasias da Mama/patologia , Aberrações Cromossômicas , Variações do Número de Cópias de DNA , Feminino , Rearranjo Gênico , Humanos , Células MCF-7 , Proteínas Adaptadoras da Sinalização Shc/genética
6.
Mol Oncol ; 16(14): 2632-2657, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34967509

RESUMO

Despite the current standard of care, breast cancer remains one of the leading causes of mortality in women worldwide, thus emphasizing the need for better predictive and therapeutic targets. ABI1 is associated with poor survival and an aggressive breast cancer phenotype, although its role in tumorigenesis, metastasis, and the disease outcome remains to be elucidated. Here, we define the ABI1-based seven-gene prognostic signature that predicts survival of metastatic breast cancer patients; ABI1 is an essential component of the signature. Genetic disruption of Abi1 in primary breast cancer tumors of PyMT mice led to significant reduction of the number and size of lung metastases in a gene dose-dependent manner. The disruption of Abi1 resulted in deregulation of the WAVE complex at the mRNA and protein levels in mouse tumors. In conclusion, ABI1 is a prognostic metastatic biomarker in breast cancer. We demonstrate, for the first time, that lung metastasis is associated with an Abi1 gene dose and specific gene expression aberrations in primary breast cancer tumors. These results indicate that targeting ABI1 may provide a therapeutic advantage in breast cancer patients.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias da Mama , Proteínas do Citoesqueleto , Neoplasias Pulmonares , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinogênese/genética , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Camundongos , Metástase Neoplásica
7.
Artigo em Inglês | MEDLINE | ID: mdl-36688938

RESUMO

Our understanding of the molecular functions of the nucleocytoplasmic FMRP protein, which, if absent or dysfunctional, causes the fragile X syndrome (FXS), largely revolves around its involvement in protein translation regulation in the cytoplasm. Recent studies have begun honing in on the nuclear and genomic functions of FMRP. We have shown that during DNA replication stress, cells derived from FXS patients sustain increased level of R-loop formation and DNA double strand breaks. Here, we describe a transcriptomic analysis of these cells in order to identify those genes most impacted by the loss of FMRP with and without replication stress. We show that FMRP loss causes transcriptomic changes previously reported in untreated conditions. Importantly, we also show that replication stress, in addition to causing excess of DSB, results in down-regulation of transcription in virtually all DNA repair pathways. This finding suggests that despite normal DNA damage response, FXS patient-derived cells experience R-loop-induced DNA breakage as well as impaired DNA repair functions, effectively a double jeopardy. We suggest that it is imperative to deepen the understanding of the nuclear functions, particularly a genome protective function, of FMRP, which will lead to discoveries of novel therapeutic interventions for the FXS.

8.
Cancers (Basel) ; 13(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202278

RESUMO

Systems cancer biology analysis of calorie restriction (CR) mechanisms and pathways has not been carried out, leaving therapeutic benefits unclear. Using metadata analysis, we studied gene expression changes in normal mouse duodenum mucosa (DM) response to short-term (2-weeks) 25% CR as a biological model. Our results indicate cancer-associated genes consist of 26% of 467 CR responding differential expressed genes (DEGs). The DEGs were enriched with over-expressed cell cycle, oncogenes, and metabolic reprogramming pathways that determine tissue-specific tumorigenesis, cancer, and stem cell activation; tumor suppressors and apoptosis genes were under-expressed. DEG enrichments suggest telomeric maintenance misbalance and metabolic pathway activation playing dual (anti-cancer and pro-oncogenic) roles. The aberrant DEG profile of DM epithelial cells is found within CR-induced overexpression of Paneth cells and is coordinated significantly across GI tract tissues mucosa. Immune system genes (ISGs) consist of 37% of the total DEGs; the majority of ISGs are suppressed, including cell-autonomous immunity and tumor-immune surveillance. CR induces metabolic reprogramming, suppressing immune mechanics and activating oncogenic pathways. We introduce and argue for our network pro-oncogenic model of the mucosa multicellular tissue response to CR leading to aberrant transcription and pre-malignant states. These findings change the paradigm regarding CR's anti-cancer role, initiating specific treatment target development. This will aid future work to define critical oncogenic pathways preceding intestinal lesion development and biomarkers for earlier adenoma and colorectal cancer detection.

9.
Front Mol Biosci ; 8: 691694, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34179096

RESUMO

R-loops are non-canonical, three-stranded nucleic acid structures composed of a DNA:RNA hybrid, a displaced single-stranded (ss)DNA, and a trailing ssRNA overhang. R-loops perform critical biological functions under both normal and disease conditions. To elucidate their cellular functions, we need to understand the mechanisms underlying R-loop formation, recognition, signaling, and resolution. Previous high-throughput screens identified multiple proteins that bind R-loops, with many of these proteins containing folded nucleic acid processing and binding domains that prevent (e.g., topoisomerases), resolve (e.g., helicases, nucleases), or recognize (e.g., KH, RRMs) R-loops. However, a significant number of these R-loop interacting Enzyme and Reader proteins also contain long stretches of intrinsically disordered regions (IDRs). The precise molecular and structural mechanisms by which the folded domains and IDRs synergize to recognize and process R-loops or modulate R-loop-mediated signaling have not been fully explored. While studying one such modular R-loop Reader, the Fragile X Protein (FMRP), we unexpectedly discovered that the C-terminal IDR (C-IDR) of FMRP is the predominant R-loop binding site, with the three N-terminal KH domains recognizing the trailing ssRNA overhang. Interestingly, the C-IDR of FMRP has recently been shown to undergo spontaneous Liquid-Liquid Phase Separation (LLPS) assembly by itself or in complex with another non-canonical nucleic acid structure, RNA G-quadruplex. Furthermore, we have recently shown that FMRP can suppress persistent R-loops that form during transcription, a process that is also enhanced by LLPS via the assembly of membraneless transcription factories. These exciting findings prompted us to explore the role of IDRs in R-loop processing and signaling proteins through a comprehensive bioinformatics and computational biology study. Here, we evaluated IDR prevalence, sequence composition and LLPS propensity for the known R-loop interactome. We observed that, like FMRP, the majority of the R-loop interactome, especially Readers, contains long IDRs that are highly enriched in low complexity sequences with biased amino acid composition, suggesting that these IDRs could directly interact with R-loops, rather than being "mere flexible linkers" connecting the "functional folded enzyme or binding domains". Furthermore, our analysis shows that several proteins in the R-loop interactome are either predicted to or have been experimentally demonstrated to undergo LLPS or are known to be associated with phase separated membraneless organelles. Thus, our overall results present a thought-provoking hypothesis that IDRs in the R-loop interactome can provide a functional link between R-loop recognition via direct binding and downstream signaling through the assembly of LLPS-mediated membrane-less R-loop foci. The absence or dysregulation of the function of IDR-enriched R-loop interactors can potentially lead to severe genomic defects, such as the widespread R-loop-mediated DNA double strand breaks that we recently observed in Fragile X patient-derived cells.

11.
Syst Biol Reprod Med ; 66(6): 364-369, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33043679

RESUMO

When considering empirical medical management (EMT) options for men with unexplained infertility (UI), clomiphene citrate (CC) has been shown to positively influence sperm parameters in hypogonadal men. Unfortunately, the optimal cut point for defining hypogonadism for this patient population has not been established. We hypothesized that hypogonadal men with UI having the lowest serum total testosterone (TT) (<265 ng/dL) would have a significant post-CC improvement in both TT and semen characteristics compared to those in the TT > 264 ng/dL group. We performed our study based on an IRB-approved retrospective chart review of 83 males with UI receiving more than 90 days of 50 mg daily CC. Serum TT and semen characteristics were studied in 83 patients before and in 23 patients after CC treatment. Median TT level increased from 256 ng/dL to 630 ng/dL (p < 0.001, n = 83) and SC increased from 6 ( 106 /ml) to 20 ( 106 /ml) (p < 0.016, n = 23). Overall, our results demonstrated the following: (1) CC treatment at all currently used serum TT cut-points resulted in significant improvement in both TT (p < 0.001) and sperm concentration (p = 0.03). No significant change in post-CC sperm motility or morphology was noted. (2) Correlation and linear regression analyses demonstrated that CC treatment significantly increased TT in 96% (22 of 23) of patients, and (3) when grouped as two cohorts (≤264 and >264 ng/dL), sperm concentration and TT improved 2.3 to 2.6-fold (p < 0.001) and 1.45 to 2.5-fold (p < 0.01) respectively. Thus, for hypogonadal men with UI, CC significantly improved TT and sperm concentration regardless of pre-treatment, baseline serum TT level. For this reason, CC treatment should be considered in men with UI having a TT < 400 ng/dL.


Assuntos
Clomifeno/uso terapêutico , Fármacos para a Fertilidade Masculina/uso terapêutico , Hipogonadismo/tratamento farmacológico , Infertilidade Masculina/tratamento farmacológico , Espermatogênese/efeitos dos fármacos , Testosterona/sangue , Adulto , Biomarcadores/sangue , Humanos , Hipogonadismo/complicações , Hipogonadismo/diagnóstico , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/etiologia , Masculino , Estudos Retrospectivos , Contagem de Espermatozoides , Fatores de Tempo , Resultado do Tratamento
12.
Cell Rep ; 32(12): 108179, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32966779

RESUMO

Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by mutations in the FMR1 gene and deficiency of a functional FMRP protein. FMRP is known as a translation repressor whose nuclear function is not understood. We investigated the global impact on genome stability due to FMRP loss. Using Break-seq, we map spontaneous and replication stress-induced DNA double-strand breaks (DSBs) in an FXS patient-derived cell line. We report that the genomes of FXS cells are inherently unstable and accumulate twice as many DSBs as those from an unaffected control. We demonstrate that replication stress-induced DSBs in FXS cells colocalize with R-loop forming sequences. Exogenously expressed FMRP in FXS fibroblasts ameliorates DSB formation. FMRP, not the I304N mutant, abates R-loop-induced DSBs during programmed replication-transcription conflict. These results suggest that FMRP is a genome maintenance protein that prevents R-loop accumulation. Our study provides insights into the etiological basis for FXS.


Assuntos
Quebra Cromossômica , Replicação do DNA , Síndrome do Cromossomo X Frágil/genética , Genoma Humano , Estresse Fisiológico , Afidicolina/farmacologia , Linhagem Celular , Quebra Cromossômica/efeitos dos fármacos , DNA/metabolismo , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Humanos , Modelos Biológicos , Mutação/genética , Estruturas R-Loop , RNA/metabolismo , Estresse Fisiológico/efeitos dos fármacos
13.
Can J Urol ; 27(4): 10306-10311, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32861256

RESUMO

INTRODUCTION: Men with unexplained infertility (UI) should undergo an initial hormonal evaluation including serum FSH and total testosterone (TT). Unfortunately, there is no consensus regarding which TT cut point should be used to define hypogonadism in such men. To determine the best definition for hypogonadism, three different, literature-based TT cut points were used to assess associations between TT and semen parameters. The hypothesis was that the lowest TT cut point would associate with poorest sperm parameters. MATERIALS AND METHODS: We performed an IRB-approved retrospective chart review of 247 consecutive males presenting for evaluation of male factor infertility. After exclusions, basic statistics and correlation analysis of semen analysis parameters, TT, age, and body mass index (BMI) were evaluated on 128 men (age 34+/-33.5) categorized by three different TT cut points: 65 males were hypogonadal according to a TT cutoff of < 264; 16 with a cutoff of 264-300; 44 with a cutoff of 301-400; and 42 with a TT over 400 ng/dL. Basic statistics, one-way ANOVA and Levene comparative analysis were performed. Besides a negative correlation between TT and BMI, there was no significant association between the three TT literature-based cut points and the other studied parameters. These findings were further supported by multiple comparison analyses. RESULTS: For men with UI, regardless of how hypogonadism was defined, no relationship between semen parameters and TT was found. CONCLUSION: Conventional, TT-based definitions of male hypogonadism in the setting of UI need to be clarified. Clinically relevant, accurate and reproducible multivariable biomarkers need to be investigated to further advance best practices for treating men with UI.


Assuntos
Hipogonadismo/sangue , Hipogonadismo/diagnóstico , Testosterona/sangue , Adulto , Humanos , Infertilidade Masculina/etiologia , Masculino , Estudos Retrospectivos , Análise do Sêmen
14.
Cell Commun Signal ; 17(1): 120, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31530281

RESUMO

BACKGROUND: Prostate cancer development involves various mechanisms, which are poorly understood but pointing to epithelial mesenchymal transition (EMT) as the key mechanism in progression to metastatic disease. ABI1, a member of WAVE complex and actin cytoskeleton regulator and adaptor protein, acts as tumor suppressor in prostate cancer but the role of ABI1 in EMT is not clear. METHODS: To investigate the molecular mechanism by which loss of ABI1 contributes to tumor progression, we disrupted the ABI1 gene in the benign prostate epithelial RWPE-1 cell line and determined its phenotype. Levels of ABI1 expression in prostate organoid tumor cell lines was evaluated by Western blotting and RNA sequencing. ABI1 expression and its association with prostate tumor grade was evaluated in a TMA cohort of 505 patients and metastatic cell lines. RESULTS: Low ABI1 expression is associated with biochemical recurrence, metastasis and death (p = 0.038). Moreover, ABI1 expression was significantly decreased in Gleason pattern 5 vs. pattern 4 (p = 0.0025) and 3 (p = 0.0012), indicating an association between low ABI1 expression and highly invasive prostate tumors. Disruption of ABI1 gene in RWPE-1 cell line resulted in gain of an invasive phenotype, which was characterized by a loss of cell-cell adhesion markers and increased migratory ability of RWPE-1 spheroids. Through RNA sequencing and protein expression analysis, we discovered that ABI1 loss leads to activation of non-canonical WNT signaling and EMT pathways, which are rescued by re-expression of ABI1. Furthermore, an increase in STAT3 phosphorylation upon ABI1 inactivation and the evidence of a high-affinity interaction between the FYN SH2 domain and ABI1 pY421 support a model in which ABI1 acts as a gatekeeper of non-canonical WNT-EMT pathway activation downstream of the FZD2 receptor. CONCLUSIONS: ABI1 controls prostate tumor progression and epithelial plasticity through regulation of EMT-WNT pathway. Here we discovered that ABI1 inhibits EMT through suppressing FYN-STAT3 activation downstream from non-canonical WNT signaling thus providing a novel mechanism of prostate tumor suppression.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinogênese/genética , Proteínas do Citoesqueleto/deficiência , Proteínas do Citoesqueleto/genética , Transição Epitelial-Mesenquimal/genética , Técnicas de Inativação de Genes , Neoplasias da Próstata/patologia , Via de Sinalização Wnt/genética , Caderinas/metabolismo , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Receptores Frizzled/metabolismo , Humanos , Masculino , Gradação de Tumores , Fenótipo , Recidiva , Fator de Transcrição STAT3/metabolismo , Regulação para Cima/genética , beta Catenina/metabolismo
15.
JACC Basic Transl Sci ; 3(2): 163-175, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30062203

RESUMO

We identified a plasma signature of 11 C14 to C26 ceramides and 1 C16 dihydroceramide predictive of major adverse cardiovascular events in patients with acute myocardial infarction (AMI). Among patients undergoing coronary artery bypass surgery, those with recent AMI, compared with those without recent AMI, showed a significant increase in 5 of the signature's 12 ceramides in plasma but not simultaneously-biopsied aortic tissue. In contrast, a rat AMI model, compared with sham control, showed a significant increase in myocardial concentrations of all 12 ceramides and up-regulation of 3 ceramide-producing enzymes, suggesting ischemic myocardium as a possible source of this ceramide signature.

17.
Sci Rep ; 8(1): 11338, 2018 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-30054525

RESUMO

The intestine is key for nutrient absorption and for interactions between the microbiota and its host. Therefore, the intestinal response to caloric restriction (CR) is thought to be more complex than that of any other organ. Submitting mice to 25% CR during 14 days induced a polarization of duodenum mucosa cell gene expression characterised by upregulation, and downregulation of the metabolic and immune/inflammatory pathways, respectively. The HNF, PPAR, STAT, and IRF families of transcription factors, particularly the Pparα and Isgf3 genes, were identified as potentially critical players in these processes. The impact of CR on metabolic genes in intestinal mucosa was mimicked by inhibition of the mTOR pathway. Furthermore, multiple duodenum and faecal metabolites were altered in CR mice. These changes were dependent on microbiota and their magnitude corresponded to microbial density. Further experiments using mice with depleted gut bacteria and CR-specific microbiota transfer showed that the gene expression polarization observed in the mucosa of CR mice is independent of the microbiota and its metabolites. The holistic interdisciplinary approach that we applied allowed us to characterize various regulatory aspects of the host and microbiota response to CR.


Assuntos
Restrição Calórica , Mucosa Intestinal/microbiologia , Microbiota , Animais , Duodeno/metabolismo , Fezes , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Inflamação/genética , Inflamação/patologia , Mucosa Intestinal/metabolismo , Masculino , Metaboloma , Camundongos Endogâmicos C57BL , Modelos Biológicos , Serina-Treonina Quinases TOR/metabolismo
18.
Nucleic Acids Res ; 46(15): 7566-7585, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-29945198

RESUMO

R-loops are three-stranded RNA:DNA hybrid structures essential for many normal and pathobiological processes. Previously, we generated a quantitative R-loop forming sequence (RLFS) model, quantitative model of R-loop-forming sequences (QmRLFS) and predicted ∼660 000 RLFSs; most of them located in genes and gene-flanking regions, G-rich regions and disease-associated genomic loci in the human genome. Here, we conducted a comprehensive comparative analysis of these RLFSs using experimental data and demonstrated the high performance of QmRLFS predictions on the nucleotide and genome scales. The preferential co-localization of RLFS with promoters, U1 splice sites, gene ends, enhancers and non-B DNA structures, such as G-quadruplexes, provides evidence for the mechanical linkage between DNA tertiary structures, transcription initiation and R-loops in critical regulatory genome regions. We introduced and characterized an abundant class of reverse-forward RLFS clusters highly enriched in non-B DNA structures, which localized to promoters, gene ends and enhancers. The RLFS co-localization with promoters and transcriptionally active enhancers suggested new models for in cis and in trans regulation by RNA:DNA hybrids of transcription initiation and formation of 3D-chromatin loops. Overall, this study provides a rationale for the discovery and characterization of the non-B DNA regulatory structures involved in the formation of the RNA:DNA interactome as the basis for an emerging quantitative R-loop biology and pathobiology.


Assuntos
Biologia Computacional/métodos , Elementos Facilitadores Genéticos/genética , Quadruplex G , Genoma Humano/genética , Regiões Promotoras Genéticas/genética , DNA/química , DNA/genética , DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Células K562 , Conformação de Ácido Nucleico , RNA/química , RNA/genética , RNA/metabolismo , Transcrição Gênica
19.
Data Brief ; 17: 1112-1135, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29876469

RESUMO

This article contains further data and information from our published manuscript [1]. We aim to identify significant transcriptome alterations of vascular smooth muscle cells (VSMCs) in the aortic wall of myocardial infarction (MI) patients. Microarray gene analysis was applied to evaluate VSMCs of MI and non-MI patients. Prediction Analysis of Microarray (PAM) identified genes that significantly discriminated the two groups of samples. Incorporation of gene ontology (GO) identified a VSMCs-associated classifier that discriminated between the two groups of samples. Mass spectrometry-based iTRAQ analysis revealed proteins significantly differentiating these two groups of samples. Ingenuity Pathway Analysis (IPA) revealed top pathways associated with hypoxia signaling in cardiovascular system. Enrichment analysis of these proteins suggested an activated pathway, and an integrated transcriptome-proteome pathway analysis revealed that it is the most implicated pathway. The intersection of the top candidate molecules from the transcriptome and proteome highlighted overexpression.

20.
Physiol Genomics ; 50(8): 648-657, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29775430

RESUMO

Myocardial infarction (MI) induced by acute coronary arterial occlusion is usually secondary to atherosclerotic plaque rupture. Dysregulated response of vascular smooth muscle cells (VSMCs) in atherosclerotic plaques may promote plaque rupture. Cadherins (CDHs) form adherens junctions and are known stabilizers of atherosclerotic plaques. To date, the expression patterns of cadherin have not been well investigated in MI aortic VSMCs. We aimed to investigate the expression of cadherin genes in the aortic wall of patients with and without MI. Laser capture microdissected VSMCs were obtained from aortic tissue samples of patients undergoing coronary artery bypass graft surgery. Integrative bioinformatic analysis of the microarray profiles of the VSMCs revealed that MI is discriminated at the whole transcriptome level by hundreds of differentially expressed genes, including genes involved in cell adhesion, of which the cadherin superfamily genes were among the top structural category. Eleven significantly deregulated candidates of the cadherin superfamily were chosen and formed a new classifier that collectively discriminated MI vs. non-MI with ~95% accuracy. Significance validation was performed with an independent cohort by quantitative RT-quantitative PCR, confirming overexpression of CDH2, CDH12, PCDH17, and PCDH18 in MI VSMCs. The dysregulation of these cadherin superfamily genes might be related to an MI-induced remote effect on aortic wall VSMCs and to imbalances in signaling pathways and myocardial repair mechanisms. Although pathophysiological significance of our findings requires functional studies, mRNA upregulation of the identified cadherin superfamily members in VSMCs might be associated with the progression of atherosclerosis and angiogenesis activation in MI.


Assuntos
Caderinas/genética , Perfilação da Expressão Gênica/métodos , Infarto do Miocárdio/genética , Miócitos de Músculo Liso/metabolismo , Regulação para Cima , Aorta/patologia , Células Cultivadas , Progressão da Doença , Ontologia Genética , Humanos , Músculo Liso Vascular/patologia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Isoformas de Proteínas/genética
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