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1.
JHEP Rep ; 5(6): 100715, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37168287

RESUMO

Background & Aims: Lifestyle and environmental-related exposures are important risk factors for hepatocellular carcinoma (HCC), suggesting that epigenetic dysregulation significantly underpins HCC. We profiled 30 surgically resected tumours and the matched adjacent normal tissues to understand the aberrant epigenetic events associated with HCC. Methods: We identified tumour differential enhancers and the associated genes by analysing H3K27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing (ChIP-seq) and Hi-C/HiChIP data from the resected tumour samples of 30 patients with early-stage HCC. This epigenome dataset was analysed with previously reported genome and transcriptome data of the overlapping group of patients from the same cohort. We performed patient-specific differential expression testing using multiregion sequencing data to identify genes that undergo both enhancer and gene expression changes. Based on the genes selected, we identified two patient groups and performed a recurrence-free survival analysis. Results: We observed large-scale changes in the enhancer distribution between HCC tumours and the adjacent normal samples. Many of the gain-in-tumour enhancers showed corresponding upregulation of the associated genes and vice versa, but much of the enhancer and gene expression changes were patient-specific. A subset of the upregulated genes was activated in a subgroup of patients' tumours. Recurrence-free survival analysis revealed that the patients with a more robust upregulation of those genes showed a worse prognosis. Conclusions: We report the genomic enhancer signature associated with differential prognosis in HCC. Findings that cohere with oncofoetal reprogramming in HCC were underpinned by genome-wide enhancer rewiring. Our results present the epigenetic changes in HCC that offer the rational selection of epigenetic-driven gene targets for therapeutic intervention or disease prognostication in HCC. Impact and Implications: Lifestyle and environmental-related exposures are the important risk factors of hepatocellular carcinoma (HCC), suggesting that tumour-associated epigenetic dysregulations may significantly underpin HCC. We profiled tumour tissues and their matched normal from 30 patients with early-stage HCC to study the dysregulated epigenetic changes associated with HCC. By also analysing the patients' RNA-seq and clinical data, we found the signature genes - with epigenetic and transcriptomic dysregulation - associated with worse prognosis. Our findings suggest that systemic approaches are needed to consider the surrounding cellular environmental and epigenetic changes in HCC tumours.

2.
Gut ; 72(9): 1651-1663, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36918265

RESUMO

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer mortality, with ARID1A being the second most frequently mutated driver gene in GC. We sought to decipher ARID1A-specific GC regulatory networks and examine therapeutic vulnerabilities arising from ARID1A loss. DESIGN: Genomic profiling of GC patients including a Singapore cohort (>200 patients) was performed to derive mutational signatures of ARID1A inactivation across molecular subtypes. Single-cell transcriptomic profiles of ARID1A-mutated GCs were analysed to examine tumour microenvironmental changes arising from ARID1A loss. Genome-wide ARID1A binding and chromatin profiles (H3K27ac, H3K4me3, H3K4me1, ATAC-seq) were generated to identify gastric-specific epigenetic landscapes regulated by ARID1A. Distinct cancer hallmarks of ARID1A-mutated GCs were converged at the genomic, single-cell and epigenomic level, and targeted by pharmacological inhibition. RESULTS: We observed prevalent ARID1A inactivation across GC molecular subtypes, with distinct mutational signatures and linked to a NFKB-driven proinflammatory tumour microenvironment. ARID1A-depletion caused loss of H3K27ac activation signals at ARID1A-occupied distal enhancers, but unexpectedly gain of H3K27ac at ARID1A-occupied promoters in genes such as NFKB1 and NFKB2. Promoter activation in ARID1A-mutated GCs was associated with enhanced gene expression, increased BRD4 binding, and reduced HDAC1 and CTCF occupancy. Combined targeting of promoter activation and tumour inflammation via bromodomain and NFKB inhibitors confirmed therapeutic synergy specific to ARID1A-genomic status. CONCLUSION: Our results suggest a therapeutic strategy for ARID1A-mutated GCs targeting both tumour-intrinsic (BRD4-assocatiated promoter activation) and extrinsic (NFKB immunomodulation) cancer phenotypes.


Assuntos
Neoplasias Gástricas , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patologia , Proteínas Nucleares/genética , Epigenômica , Mutação , Microambiente Tumoral/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ciclo Celular/genética
5.
BMC Cancer ; 23(1): 118, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737737

RESUMO

BACKGROUND: Conventional differential expression (DE) testing compares the grouped mean value of tumour samples to the grouped mean value of the normal samples, and may miss out dysregulated genes in small subgroup of patients. This is especially so for highly heterogeneous cancer like Hepatocellular Carcinoma (HCC). METHODS: Using multi-region sampled RNA-seq data of 90 patients, we performed patient-specific differential expression testing, together with the patients' matched adjacent normal samples. RESULTS: Comparing the results from conventional DE analysis and patient-specific DE analyses, we show that the conventional DE analysis omits some genes due to high inter-individual variability present in both tumour and normal tissues. Dysregulated genes shared in small subgroup of patients were useful in stratifying patients, and presented differential prognosis. We also showed that the target genes of some of the current targeted agents used in HCC exhibited highly individualistic dysregulation pattern, which may explain the poor response rate. DISCUSSION/CONCLUSION: Our results highlight the importance of identifying patient-specific DE genes, with its potential to provide clinically valuable insights into patient subgroups for applications in precision medicine.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Prognóstico , Regulação Neoplásica da Expressão Gênica
6.
Gut ; 72(2): 226-241, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35817555

RESUMO

OBJECTIVE: Gastric cancer (GC) comprises multiple molecular subtypes. Recent studies have highlighted mesenchymal-subtype GC (Mes-GC) as a clinically aggressive subtype with few treatment options. Combining multiple studies, we derived and applied a consensus Mes-GC classifier to define the Mes-GC enhancer landscape revealing disease vulnerabilities. DESIGN: Transcriptomic profiles of ~1000 primary GCs and cell lines were analysed to derive a consensus Mes-GC classifier. Clinical and genomic associations were performed across >1200 patients with GC. Genome-wide epigenomic profiles (H3K27ac, H3K4me1 and assay for transposase-accessible chromatin with sequencing (ATAC-seq)) of 49 primary GCs and GC cell lines were generated to identify Mes-GC-specific enhancer landscapes. Upstream regulators and downstream targets of Mes-GC enhancers were interrogated using chromatin immunoprecipitation followed by sequencing (ChIP-seq), RNA sequencing, CRISPR/Cas9 editing, functional assays and pharmacological inhibition. RESULTS: We identified and validated a 993-gene cancer-cell intrinsic Mes-GC classifier applicable to retrospective cohorts or prospective single samples. Multicohort analysis of Mes-GCs confirmed associations with poor patient survival, therapy resistance and few targetable genomic alterations. Analysis of enhancer profiles revealed a distinctive Mes-GC epigenomic landscape, with TEAD1 as a master regulator of Mes-GC enhancers and Mes-GCs exhibiting preferential sensitivity to TEAD1 pharmacological inhibition. Analysis of Mes-GC super-enhancers also highlighted NUAK1 kinase as a downstream target, with synergistic effects observed between NUAK1 inhibition and cisplatin treatment. CONCLUSION: Our results establish a consensus Mes-GC classifier applicable to multiple transcriptomic scenarios. Mes-GCs exhibit a distinct epigenomic landscape, and TEAD1 inhibition and combinatorial NUAK1 inhibition/cisplatin may represent potential targetable options.


Assuntos
Elementos Facilitadores Genéticos , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Gástricas , Humanos , Cisplatino/metabolismo , Cisplatino/uso terapêutico , Estudos Prospectivos , Proteínas Quinases/genética , Proteínas Repressoras , Estudos Retrospectivos , Neoplasias Gástricas/genética
7.
Atherosclerosis ; 362: 11-22, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36435092

RESUMO

BACKGROUND AND AIMS: Single nucleotide polymorphism rs6903956 has been identified as one of the genetic risk factors for coronary artery disease (CAD). However, rs6903956 lies in a non-coding locus on chromosome 6p24.1. We aim to interrogate the molecular basis of 6p24.1 containing rs6903956 risk alleles in endothelial disease biology. METHODS AND RESULTS: We generated induced pluripotent stem cells (iPSCs) from CAD patients (AA risk genotype at rs6903956) and non-CAD subjects (GG non-risk genotype at rs6903956). CRISPR-Cas9-based deletions (Δ63-89bp) on 6p24.1, including both rs6903956 and a short tandem repeat variant rs140361069 in linkage disequilibrium, were performed to generate isogenic iPSC-derived endothelial cells. Edited CAD endothelial cells, with removal of 'A' risk alleles, exhibited a global transcriptional downregulation of pathways relating to abnormal vascular physiology and activated endothelial processes. A CXC chemokine ligand on chromosome 10q11.21, CXCL12, was uncovered as a potential effector gene in CAD endothelial cells. Underlying this effect was the preferential inter-chromosomal interaction of 6p24.1 risk locus to a weak promoter of CXCL12, confirmed by chromatin conformation capture assays on our iPSC-derived endothelial cells. Functionally, risk genotypes AA/AG at rs6903956 were associated significantly with elevated levels of circulating damaged endothelial cells in CAD patients. Circulating endothelial cells isolated from patients with risk genotypes AA/AG were also found to have 10 folds higher CXCL12 transcript copies/cell than those with non-risk genotype GG. CONCLUSIONS: Our study reveals the trans-acting impact of 6p24.1 with another CAD locus on 10q11.21 and is associated with intensified endothelial injury.


Assuntos
Doença da Artéria Coronariana , Células Endoteliais , Humanos , Doença da Artéria Coronariana/genética , Alelos , Genótipo , Polimorfismo de Nucleotídeo Único
8.
Adv Sci (Weinh) ; 9(31): e2202834, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35975420

RESUMO

Rho GTPases and Hippo kinases are key regulators of cardiomyoblast differentiation. However, how these signaling axes are coordinated spatiotemporally remains unclear. Here, the central and multifaceted roles of the BCH domain containing protein, BNIP-2, in orchestrating the expression of two key cardiac genes (cardiac troponin T [cTnT] and cardiac myosin light chain [Myl2]) in H9c2 and human embryonic stem cell-derived cardiomyocytes are delineated. This study shows that BNIP-2 mRNA and protein expression increase with the onset of cTnT and Myl2 and promote the alignment of H9c2 cardiomyocytes. Mechanistically, BNIP-2 is required for the inactivation of YAP through YAP phosphorylation and its cytosolic retention. Turbo-ID proximity labeling corroborated by super-resolution analyses and biochemical pulldown data reveals a scaffolding role of BNIP-2 for LATS1 to phosphorylate and inactivate YAP in a process that requires BNIP-2 activation of cellular contractility. The findings identify BNIP-2 as a pivotal signaling scaffold that spatiotemporally integrates RhoA/Myosin II and LATS1/YAP mechanotransduction signaling to drive cardiomyoblast differentiation, by switching the genetic programming from YAP-dependent growth to YAP-silenced differentiation. These findings offer insights into the importance of scaffolding proteins in bridging the gap between mechanical and biochemical signals in cell growth and differentiation and the prospects in translational applications.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Transporte , Mecanotransdução Celular , Miócitos Cardíacos , Proteínas de Sinalização YAP , Humanos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Diferenciação Celular , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Animais , Ratos , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Miócitos Cardíacos/citologia , Proteínas de Sinalização YAP/genética , Proteínas de Sinalização YAP/metabolismo
9.
J Hypertens ; 40(6): 1179-1188, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35703880

RESUMO

OBJECTIVE: Adrenal vein sampling (AVS) is recommended to subtype primary aldosteronism, but it is technically challenging. We compared 11C-Metomidate-PET-computed tomography (PET-CT) and AVS for subtyping of primary aldosteronism. METHODS: Patients with confirmed primary aldosteronism underwent both AVS and 11C-Metomidate PET-CT (post-dexamethasone). All results were reviewed at a multidisciplinary meeting to decide on final subtype diagnosis. Primary outcome was accuracy of PET versus AVS to diagnosis of unilateral primary aldosteronism based on post-surgical biochemical cure. Secondary outcome was accuracy of both tests to final subtype diagnosis. RESULTS: All 25 patients recruited underwent PET and successful AVS (100%). Final diagnosis was unilateral in 22 patients, bilateral in two and indeterminate in one due to discordant lateralization. Twenty patients with unilateral primary aldosteronism underwent surgery, with 100% complete biochemical success, and 75% complete/partial clinical success. For the primary outcome, sensitivity of PET was 80% [95% confidence interval (95% CI): 56.3-94.3] and AVS was 75% (95% CI: 50.9-91.3). For the secondary outcome, sensitivity and specificity of PET was 81.9% (95% CI: 59.7-94.8) and 100% (95% CI: 15.8-100), and AVS was 68.2% (95% CI: 45.1-86.1) and 100% (95% CI: 15.8-100), respectively. Twelve out of 20 (60%) patients had both PET and AVS lateralization, four (20%) PET-only, three (15%) AVS-only, while one patient did not lateralize on PET or AVS. Post-surgery outcomes did not differ between patients identified by either test. CONCLUSION: In our pilot study, 11C-Metomidate PET-CT performed comparably to AVS, and this should be validated in larger studies. PET identified patients with unilateral primary aldosteronism missed on AVS, and these tests could be used together to identify more patients with unilateral primary aldosteronism. VIDEO ABSTRACT: http://links.lww.com/HJH/B918.


Assuntos
Hiperaldosteronismo , Glândulas Suprarrenais/irrigação sanguínea , Aldosterona , Radioisótopos de Carbono , Etomidato/análogos & derivados , Humanos , Hiperaldosteronismo/diagnóstico por imagem , Hiperaldosteronismo/cirurgia , Projetos Piloto , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Prospectivos , Estudos Retrospectivos
10.
Theranostics ; 12(7): 3007-3023, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35547760

RESUMO

Objective: Vascular dementia (VaD) is the second most common cause of dementia worldwide. The increasing contribution of lifestyle-associated risk factors to VaD has pointed towards gene-environment interactions (i.e. epigenetics). This study thus aims to investigate the DNA methylation landscape in a chronic cerebral hypoperfusion (CCH) mouse model of VaD. As a nexus between the gene-environment interaction, intermittent fasting (IF) was introduced as a prophylactic intervention. Methods: Bilateral common carotid artery stenosis (BCAS) was used to induce CCH by placing micro-coils of 0.18 mm in each common carotid artery of the mice. The coils were left in the mice for 7, 15 and 30 days to study temporal differences. IF was introduced for 16 h daily for 4 months prior to BCAS. Reduced Representation Bisulfite Sequencing (RRBS) was used to study the DNA methylation landscape. Cognitive impairment was measured using Barnes Maze Test. White matter lesions (WML) and neuronal loss were measured using Luxol fast blue staining and cresyl violet staining respectively. Results: IF mice subjected to CCH displayed significantly better cognitive learning ability and memory, improved neuropathological alterations with reduced WMLs and neuronal loss. Modulation of DNA methylation patterns in the cortex of AL CCH mice was re-modelled and signs of reversal was observed in IF CCH mice across all three timepoints. Conclusions: These findings provide an understanding of how IF may protect the brain against damage caused by CCH and show promise in offering potential beneficial effects in mitigating the neuropathology and cognitive deficits in VaD.


Assuntos
Isquemia Encefálica , Estenose das Carótidas , Disfunção Cognitiva , Demência Vascular , Animais , Isquemia Encefálica/complicações , Estenose das Carótidas/complicações , Circulação Cerebrovascular/fisiologia , Disfunção Cognitiva/patologia , Metilação de DNA , Modelos Animais de Doenças , Jejum , Aprendizagem em Labirinto , Camundongos
11.
Natl Sci Rev ; 9(3): nwab192, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35382356

RESUMO

Intra-tumor heterogeneity (ITH) is a key challenge in cancer treatment, but previous studies have focused mainly on the genomic alterations without exploring phenotypic (transcriptomic and immune) heterogeneity. Using one of the largest prospective surgical cohorts for hepatocellular carcinoma (HCC) with multi-region sampling, we sequenced whole genomes and paired transcriptomes from 67 HCC patients (331 samples). We found that while genomic ITH was rather constant across stages, phenotypic ITH had a very different trajectory and quickly diversified in stage II patients. Most strikingly, 30% of patients were found to contain more than one transcriptomic subtype within a single tumor. Such phenotypic ITH was found to be much more informative in predicting patient survival than genomic ITH and explains the poor efficacy of single-target systemic therapies in HCC. Taken together, we not only revealed an unprecedentedly dynamic landscape of phenotypic heterogeneity in HCC, but also highlighted the importance of studying phenotypic evolution across cancer types.

12.
Oxid Med Cell Longev ; 2022: 9180267, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35391931

RESUMO

Doxorubicin is an anthracycline widely used for the treatment of various cancers; however, the drug has a common deleterious side effect, namely a dose-dependent cardiotoxicity. Doxorubicin treatment increases the generation of reactive oxygen species, which leads to oxidative stress in the cardiac cells and ultimately DNA damage and cell death. The most common DNA lesion produced by oxidative stress is 7,8-dihydro-8-oxoguanine (8-oxoguanine), and the enzyme responsible for its repair is the 8-oxoguanine DNA glycosylase (OGG1), a base excision repair enzyme. Here, we show that the OGG1 deficiency has no major effect on cardiac function at baseline or with pressure overload; however, we found an exacerbation of cardiac dysfunction as well as a higher mortality in Ogg1 knockout mice treated with doxorubicin. Our transcriptomic analysis also showed a more extensive dysregulation of genes in the hearts of Ogg1 knockout mice with an enrichment of genes involved in inflammation. These results demonstrate that OGG1 attenuates doxorubicin-induced cardiotoxicity and thus plays a role in modulating drug-induced cardiomyopathy.


Assuntos
DNA Glicosilases , Cardiopatias , Animais , Cardiotoxicidade , Dano ao DNA , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Reparo do DNA , Doxorrubicina/efeitos adversos , Guanina/análogos & derivados , Camundongos , Camundongos Knockout , Estresse Oxidativo
13.
Geroscience ; 44(4): 2171-2194, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35357643

RESUMO

Intermittent fasting (IF) remains the most effective intervention to achieve robust anti-aging effects and attenuation of age-related diseases in various species. Epigenetic modifications mediate the biological effects of several environmental factors on gene expression; however, no information is available on the effects of IF on the epigenome. Here, we first found that IF for 3 months caused modulation of H3K9 trimethylation (H3K9me3) in the cerebellum, which in turn orchestrated a plethora of transcriptomic changes involved in robust metabolic switching processes commonly observed during IF. Second, a portion of both the epigenomic and transcriptomic modulations induced by IF was remarkably preserved for at least 3 months post-IF refeeding, indicating that memory of IF-induced epigenetic changes was maintained. Notably, though, we found that termination of IF resulted in a loss of H3K9me3 regulation of the transcriptome. Collectively, our study characterizes the novel effects of IF on the epigenetic-transcriptomic axis, which controls myriad metabolic processes. The comprehensive analyses undertaken in this study reveal a molecular framework for understanding how IF impacts the metabolo-epigenetic axis of the brain and will serve as a valuable resource for future research.


Assuntos
Epigenômica , Transcriptoma , Jejum , Perfilação da Expressão Gênica , Encéfalo
14.
Genome Med ; 13(1): 158, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635154

RESUMO

BACKGROUND: Enhancers are distal cis-regulatory elements required for cell-specific gene expression and cell fate determination. In cancer, enhancer variation has been proposed as a major cause of inter-patient heterogeneity-however, most predicted enhancer regions remain to be functionally tested. METHODS: We analyzed 132 epigenomic histone modification profiles of 18 primary gastric cancer (GC) samples, 18 normal gastric tissues, and 28 GC cell lines using Nano-ChIP-seq technology. We applied Capture-based Self-Transcribing Active Regulatory Region sequencing (CapSTARR-seq) to assess functional enhancer activity. An Activity-by-contact (ABC) model was employed to explore the effects of histone acetylation and CapSTARR-seq levels on enhancer-promoter interactions. RESULTS: We report a comprehensive catalog of 75,730 recurrent predicted enhancers, the majority of which are GC-associated in vivo (> 50,000) and associated with lower somatic mutation rates inferred by whole-genome sequencing. Applying CapSTARR-seq to the enhancer catalog, we observed significant correlations between CapSTARR-seq functional activity and H3K27ac/H3K4me1 levels. Super-enhancer regions exhibited increased CapSTARR-seq signals compared to regular enhancers, even when decoupled from native chromatin contexture. We show that combining histone modification and CapSTARR-seq functional enhancer data improves the prediction of enhancer-promoter interactions and pinpointing of germline single nucleotide polymorphisms (SNPs), somatic copy number alterations (SCNAs), and trans-acting TFs involved in GC expression. We identified cancer-relevant genes (ING1, ARL4C) whose expression between patients is influenced by enhancer differences in genomic copy number and germline SNPs, and HNF4α as a master trans-acting factor associated with GC enhancer heterogeneity. CONCLUSIONS: Our results indicate that combining histone modification and functional assay data may provide a more accurate metric to assess enhancer activity than either platform individually, providing insights into the relative contribution of genetic (cis) and regulatory (trans) mechanisms to GC enhancer functional heterogeneity.


Assuntos
Elementos Facilitadores Genéticos , Epigenômica , Neoplasias Gástricas/genética , Fatores de Ribosilação do ADP/genética , Fatores de Ribosilação do ADP/metabolismo , Acetilação , Linhagem Celular Tumoral , Proliferação de Células , Cromatina , Regulação Neoplásica da Expressão Gênica , Genômica , Histonas/metabolismo , Humanos , Proteína 1 Inibidora do Crescimento/genética , Proteína 1 Inibidora do Crescimento/metabolismo , Oncogenes , Regiões Promotoras Genéticas , RNA-Seq , Transcriptoma , Sequenciamento Completo do Genoma
15.
PLoS Genet ; 17(9): e1009741, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499641

RESUMO

Much has been written about gene modifying technologies (GMTs), with a particularly strong focus on human germline genome editing (HGGE) sparked by its unprecedented clinical research application in 2018, shocking the scientific community. This paper applies political, ethical, and social lenses to aspects of HGGE to uncover previously underexplored considerations that are important to reflect on in global discussions. By exploring 4 areas-(1) just distribution of HGGE benefits through a realist lens; (2) HGGE through a national interest lens; (3) "broad societal consensus" through a structural injustice lens; and (4) HGGE through a scientific trustworthiness lens-a broader perspective is offered, which ultimately aims to enrich further debates and inform well-considered solutions for developments in this field. The application of these lenses also brings to light the fact that all discussions about scientific developments involve a conscious or unconscious application of a lens that shapes the direction of our thinking.


Assuntos
Ética , Genoma Humano , Mutação em Linhagem Germinativa , Política , Edição de Genes , Humanos
16.
Nat Commun ; 12(1): 4722, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354059

RESUMO

Mutations in the LaminA gene are a common cause of monogenic dilated cardiomyopathy. Here we show that mice with a cardiomyocyte-specific Lmna deletion develop cardiac failure and die within 3-4 weeks after inducing the mutation. When the same Lmna mutations are induced in mice genetically deficient in the LINC complex protein SUN1, life is extended to more than one year. Disruption of SUN1's function is also accomplished by transducing and expressing a dominant-negative SUN1 miniprotein in Lmna deficient cardiomyocytes, using the cardiotrophic Adeno Associated Viral Vector 9. The SUN1 miniprotein disrupts binding between the endogenous LINC complex SUN and KASH domains, displacing the cardiomyocyte KASH complexes from the nuclear periphery, resulting in at least a fivefold extension in lifespan. Cardiomyocyte-specific expression of the SUN1 miniprotein prevents cardiomyopathy progression, potentially avoiding the necessity of developing a specific therapeutic tailored to treating each different LMNA cardiomyopathy-inducing mutation of which there are more than 450.


Assuntos
Cardiomiopatia Dilatada/genética , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Dependovirus/genética , Feminino , Humanos , Lamina Tipo A/deficiência , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/deficiência , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transdução Genética
17.
J Mol Cell Cardiol ; 160: 15-26, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34146546

RESUMO

AIMS: Direct cardiac reprogramming represents an attractive way to reversing heart damage caused by myocardial infarction because it removes fibroblasts, while also generating new functional cardiomyocytes. Yet, the main hurdle for bringing this technique to the clinic is the lack of efficacy with current reprogramming protocols. Here, we describe our unexpected discovery that DMSO is capable of significantly augmenting direct cardiac reprogramming in vitro. METHODS AND RESULTS: Upon induction with cardiac transcription factors- Gata4, Hand2, Mef2c and Tbx5 (GHMT), the treatment of mouse embryonic fibroblasts (MEFs) with 1% DMSO induced ~5 fold increase in Myh6-mCherry+ cells, and significantly upregulated global expression of cardiac genes, including Myh6, Ttn, Nppa, Myh7 and Ryr2. RNA-seq confirmed upregulation of cardiac gene programmes and downregulation of extracellular matrix-related genes. Treatment of TGF-ß1, DMSO, or SB431542, and the combination thereof, revealed that DMSO most likely targets a separate but parallel pathway other than TGF-ß signalling. Subsequent experiments using small molecule screening revealed that DMSO enhances direct cardiac reprogramming through inhibition of the CBP/p300 bromodomain, and not its acetyltransferase property. CONCLUSION: In conclusion, our work points to a direct molecular target of DMSO, which can be used for augmenting GHMT-induced direct cardiac reprogramming and possibly other cell fate conversion processes.


Assuntos
Reprogramação Celular/efeitos dos fármacos , Dimetil Sulfóxido/farmacologia , Fibroblastos/citologia , Miócitos Cardíacos/citologia , Domínios Proteicos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição de p300-CBP/química , Animais , Benzamidas/farmacologia , Células Cultivadas , Dioxóis/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Embrião de Mamíferos/citologia , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fator de Transcrição GATA4/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Gravidez , Fator de Crescimento Transformador beta1/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
18.
Dev Dyn ; 250(12): 1759-1777, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34056790

RESUMO

BACKGROUND: Biomechanical stimuli are known to be important to cardiac development, but the mechanisms are not fully understood. Here, we pharmacologically disrupted the biomechanical environment of wild-type zebrafish embryonic hearts for an extended duration and investigated the consequent effects on cardiac function, morphological development, and gene expression. RESULTS: Myocardial contractility was significantly diminished or abolished in zebrafish embryonic hearts treated for 72 hours from 2 dpf with 2,3-butanedione monoxime (BDM). Image-based flow simulations showed that flow wall shear stresses were abolished or significantly reduced with high oscillatory shear indices. At 5 dpf, after removal of BDM, treated embryonic hearts were maldeveloped, having disrupted cardiac looping, smaller ventricles, and poor cardiac function (lower ejected flow, bulboventricular regurgitation, lower contractility, and slower heart rate). RNA sequencing of cardiomyocytes of treated hearts revealed 922 significantly up-regulated genes and 1,698 significantly down-regulated genes. RNA analysis and subsequent qPCR and histology validation suggested that biomechanical disruption led to an up-regulation of inflammatory and apoptotic genes and down-regulation of ECM remodeling and ECM-receptor interaction genes. Biomechanics disruption also prevented the formation of ventricular trabeculation along with notch1 and erbb4a down-regulation. CONCLUSIONS: Extended disruption of biomechanical stimuli caused maldevelopment, and potential genes responsible for this are identified.


Assuntos
Fenômenos Biomecânicos/efeitos dos fármacos , Diacetil/análogos & derivados , Coração/embriologia , Peixe-Zebra , Animais , Animais Geneticamente Modificados , Fenômenos Biomecânicos/fisiologia , Diacetil/farmacologia , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Coração/efeitos dos fármacos , Coração/fisiologia , Hidrodinâmica , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Organogênese/efeitos dos fármacos , Organogênese/genética , Organogênese/fisiologia , Estresse Mecânico , Peixe-Zebra/embriologia , Peixe-Zebra/genética
19.
Am J Clin Nutr ; 114(1): 80-89, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33964853

RESUMO

BACKGROUND: The consumption of wolfberry (Lycium barbarum), a rich source of carotenoids and bioactive polysaccharides, may serve as a potential dietary strategy for cardiovascular disease (CVD) risk management although limited studies examined its effects as whole fruits. OBJECTIVES: To investigate the impact of wolfberry consumption as part of a healthy dietary pattern on vascular health-related outcomes and classical CVD risk factors in middle-aged and older adults in Singapore. METHODS: This is a 16-week, parallel design, randomized controlled trial. All participants (n = 40) received dietary counselling to follow healthy dietary pattern recommendations with the wolfberry group given additional instructions to cook and consume 15 g/d whole, dried wolfberry with their main meals. Biomarkers of vascular function (flow-mediated dilation, plasma total nitrate/nitrite, endothelin-1, and intercellular adhesion molecule-1), vascular structure (carotid intima-media thickness) and vascular regeneration (endothelial progenitor cell count, plasma angiopoietin 1 and angiopoietin 2), were assessed at baseline and postintervention. Serum lipid-lipoproteins and blood pressure were evaluated every 4 weeks. RESULTS: All participants showed an improved compliance toward the healthy dietary pattern. This was coupled with marked rises in total nitrate/nitrite concentrations (mean change wolfberry: 3.92 ± 1.73 nmol/mL; control: 5.01 ± 2.55 nmol/L) and reductions in endothelin-1 concentrations (wolfberry: -0.19 ± 0.06 pg/mL; control: -0.15 ± 0.08 pg/mL). Compared with the control which depicted no changes from baseline, the wolfberry group had a significantly higher HDL cholesterol (0.08 ± 0.04 mmol/L), as well as lower Framingham predicted long-term CVD risk (-0.8 ± 0.5%) and vascular age (-1.9 ± 1.0 y) postintervention. No differences were observed in the other vascular health-related outcomes. CONCLUSIONS: In middle-aged and older adults, adherence to a healthy dietary pattern improves vascular tone. Incorporating wolfberry to the diet further improves blood lipid-lipoprotein profile and may lower long-term CVD risk. This study was registered at clinicatrials.gov as NCT03535844.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Dieta Saudável , Lycium , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
20.
Trends Biotechnol ; 39(5): 427-430, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33160679

RESUMO

Recent reporting found that a number of scientists internationally knew about the experiment resulting in the birth of the first gene-edited babies well before the news broke. Because scientists have a responsibility to reveal such activities, an international governance mechanism for reporting unethical gene editing experiments should be established.


Assuntos
Edição de Genes , Células Germinativas , Projetos de Pesquisa , Edição de Genes/ética , Edição de Genes/normas , Cooperação Internacional
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