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1.
Front Med (Lausanne) ; 11: 1353406, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38745743

RESUMO

Objectives: This study aimed to assess the prevalence of frailty in cirrhosis patients and the distribution of age, sex, and body mass index (BMI) in cirrhotic patients with frailty. Methods: We performed a thorough literature search using PubMed, Embase, Web of Science, and the Cochrane Library from inception to 29 February 2024. The estimated prevalence with a 95% confidence interval (CI) was calculated with a random effect model. Subgroup analysis and sensitivity analysis were performed to assess the heterogeneity and characterize the distribution of age, sex, and body mass index (BMI) in cirrhotic patients. Publication bias was assessed by the funnel plot, Begg's test, and Egger's test. Results: The 16 included studies, which were all observational, reported a prevalence of frailty in 8,406 cirrhosis patients ranging from 9 to 65%, and the overall estimated prevalence was 27% (95% CI: 21-33%; I2 = 97.7%, P < 0.001). This meta-analysis indicated that the estimated prevalence of frailty in cirrhosis patients was high, and compared to the non-frail cohort, the frail cohort tended to have a higher mean age, with a mean age of 63.3 (95% CI: 59.9, 66.7; Z = 36.48; P < 0.001), and a larger proportion of male patients with worse liver function, with a mean of 73.5% (95% CI: 71.4, 75.5%; Z = 7.65; P < 0.001), ND in the frail cohort, 54.8% (95% CI: 43.1, 66.5%; P < 0.001) and 23.4% (95% CI: 13.2, 33.7%; P < 0.001) were classified into Child-Pugh B and C, respectively. Meanwhile, the patients in the non-frail cohort are more likely to have a higher BMI, with a mean of 28.4 (95% CI: 24.1, 32.7; Z = 13.07; P < 0.001). Conclusion: The current study suggests that cirrhosis patients have a high prevalence of frailty. Compared with the non-frail cohort, the frail patients tend to be male, older, and have a lower BMI with worse liver function.

2.
Mol Oncol ; 18(1): 170-189, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37867415

RESUMO

Endoribonuclease DICER is an RNase III enzyme that mainly processes microRNAs in the cytoplasm but also participates in nuclear functions such as chromatin remodelling, epigenetic modification and DNA damage repair. The expression of nuclear DICER is low in most human cancers, suggesting a tight regulation mechanism that is not well understood. Here, we found that ubiquitin carboxyl-terminal hydrolase 7 (USP7), a deubiquitinase, bounded to DICER and reduced its nuclear protein level by promoting its ubiquitination and degradation through MDM2, a newly identified E3 ubiquitin-protein ligase for DICER. This USP7-MDM2-DICER axis impaired histone γ-H2AX signalling and the recruitment of DNA damage response (DDR) factors, possibly by influencing the processing of small DDR noncoding RNAs. We also showed that this negative regulation of DICER by USP7 via MDM2 was relevant to human tumours using cellular and clinical data. Our findings revealed a new way to understand the role of DICER in malignant tumour development and may offer new insights into the diagnosis, treatment and prognosis of cancers.


Assuntos
Neoplasias , Ribonuclease III , Humanos , Dano ao DNA , Reparo do DNA , Neoplasias/genética , Neoplasias/tratamento farmacológico , Proteínas Nucleares/genética , Ribonuclease III/genética , Ribonuclease III/metabolismo , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Peptidase 7 Específica de Ubiquitina/genética , Peptidase 7 Específica de Ubiquitina/metabolismo , Ubiquitinação
3.
Nat Commun ; 13(1): 3907, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35798741

RESUMO

Existing knowledge of the role of epigenetic modifiers in pancreas development has exponentially increased. However, the function of TET dioxygenases in pancreatic endocrine specification remains obscure. We set out to tackle this issue using a human embryonic stem cell (hESC) differentiation system, in which TET1/TET2/TET3 triple knockout cells display severe defects in pancreatic ß-cell specification. The integrative whole-genome analysis identifies unique cell-type-specific hypermethylated regions (hyper-DMRs) displaying reduced chromatin activity and remarkable enrichment of FOXA2, a pioneer transcription factor essential for pancreatic endoderm specification. Intriguingly, TET depletion leads to significant changes in FOXA2 binding at the pancreatic progenitor stage, in which gene loci with decreased FOXA2 binding feature low levels of active chromatin modifications and enriches for bHLH motifs. Transduction of full-length TET1 but not the TET1-catalytic-domain in TET-deficient cells effectively rescues ß-cell differentiation accompanied by restoring PAX4 hypomethylation. Taking these findings together with the defective generation of functional ß-cells upon TET1-inactivation, our study unveils an essential role of TET1-dependent demethylation in establishing ß-cell identity. Moreover, we discover a physical interaction between TET1 and FOXA2 in endodermal lineage intermediates, which provides a mechanistic clue regarding the complex crosstalk between TET dioxygenases and pioneer transcription factors in epigenetic regulation during pancreas specification.


Assuntos
Dioxigenases , Fator 3-beta Nuclear de Hepatócito , Oxigenases de Função Mista , Proteínas Proto-Oncogênicas , 5-Metilcitosina/metabolismo , Diferenciação Celular/genética , Cromatina/genética , Montagem e Desmontagem da Cromatina , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Dioxigenases/metabolismo , Epigênese Genética , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo
4.
Adv Sci (Weinh) ; 9(26): e2200562, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35712764

RESUMO

G protein-coupled receptors (GPCRs) are the most common and important drug targets. However, >70% of GPCRs are undruggable or difficult to target using conventional chemical agonists/antagonists. Small nucleic acid molecules, which can sequence-specifically modulate any gene, offer a unique opportunity to effectively expand drug targets, especially those that are undruggable or difficult to address, such as GPCRs. Here, the authors report  for the first time that small activating RNAs (saRNAs) effectively modulate a GPCR for cancer treatment. Specifically, saRNAs promoting the expression of Mas receptor (MAS1), a GPCR that counteracts the classical angiotensin II pathway in cancer cell proliferation and migration, are identified. These saRNAs, delivered by an amphiphilic dendrimer vector, enhance MAS1 expression, counteracting the angiotensin II/angiotensin II Receptor Type 1 axis, and leading to significant suppression of tumorigenesis and the inhibition of tumor progression of multiple cancers in tumor-xenografted mouse models and patient-derived tumor models. This study provides not only a new strategy for cancer therapy by targeting the renin-angiotensin system, but also a new avenue to modulate GPCR signaling by RNA activation.


Assuntos
Angiotensina II , Neoplasias , Angiotensina II/metabolismo , Animais , Camundongos , Neoplasias/genética , Neoplasias/terapia , RNA/metabolismo , Receptores Acoplados a Proteínas G/genética , Sistema Renina-Angiotensina
5.
World Neurosurg ; 160: e442-e453, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35051638

RESUMO

OBJECTIVE: Hematologic biomarkers that reflect host nutritional and inflammation status have been identified to be independent prognostic factors in various malignancies. The aim of the present study was to determine the predictive value of preoperative albumin, fibrinogen, prealbumin, albumin/fibrinogen ratio, and prealbumin/fibrinogen ratio (PFR) for the prognosis of patients with glioma. METHODS: X-tile software was used to identify cutoff values of these parameters. Kaplan-Meier survival analysis and univariate and multivariate analyses based on a Cox proportional hazards regression model were used to determine whether these markers were associated with the prognosis of patients with glioma. In addition, the Harrell concordance index with variables was used to evaluate the prognostic accuracy. RESULTS: The results indicated that PFR (hazard ratio, 2.827; 95% confidence interval, 1.353-6.122; P = 0.006) is the only independent prognostic factor in patients of glioma along with clinicopathologic grade and age. c-index of predicted nomogram including PFR (0.719) for patients with glioma was higher than that without PFR (0.699). CONCLUSIONS: Our findings show that circulating preoperative PFR might be a potential negative independent prognostic biomarker for individuals with glioma.


Assuntos
Glioma , Pré-Albumina , Fibrinogênio/análise , Glioma/diagnóstico , Humanos , Estimativa de Kaplan-Meier , Prognóstico , Estudos Retrospectivos
6.
China Tropical Medicine ; (12): 1034-2022.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-974011

RESUMO

@#Abstract: Objective To investigate the distribution and antimicrobial resistance profile of the bacterial strains isolated from blood cultures in neonatal septicemia children of Neonatology Department, the First People's Hospital of Chuzhou during Jan. 2017-Dec. 2021, in order to guide clinical rational drug use. Methods The distribution and the results of antimicrobial susceptibility tests and characteristics of the pathogenic bacteria isolated from blood culture samples in neonatal septicemia children in the First Hospital of Chuzhou from Jan. 2017 to Dec. 2021 were retrospectively analyzed. The results were analyzed with WHONET 5.6 software, according to the Clinical and Laboratory Standards Institute (CLSI) 2021 breakpoints.  Results A total of 189 strains were isolated from the 4 538 sample of blood cultures, the positive rate was 4.2%, including 59(31.2%) Gram-negative bacterial strains, 130 (68.8%) Gram-positive bacterial strains. The most frequently isolates were coagulase-negative staphylococci(64.0%), Serratia liquefaciens (15.9%), Escherichia coli (3.2%), Acinetobacter lwoffii (2.6%) and Delftia acidovorans (2.6%). The prevalence of methicillin-resistant isolates was 81.8%(99/121) in coagulase-negative Staphylococci and 25.0%(1/4) in Staphylococcus aureus. No staphylococcal strains were found resistant to vancomycin, quinupristin-dalfopristin or linezolid. The sensitivity of the antibacterial drug monitored by Serratia liquefaciens was 100.0%.Conclusions Gram-positive bacterial are the main pathogen of neonatal septicemia, and is highly resistant to the common antibacterial drugs. The clinical should choose antibacterial agents reasonably according to drug sensitivity.

7.
Mol Carcinog ; 59(10): 1174-1187, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32805084

RESUMO

Long noncoding RNAs (LncRNAs) have emerged as important players in cancer biology. Increasing evidence suggests that LncRNAs are frequently dysregulated in cancer and may function as oncogenes or tumor suppressors. Urothelial carcinoma associated 1 (UCA1), a LncRNA, firstly identified in bladder transitional cell carcinoma, seems to act as an oncogene in many different types of human cancers by promoting cell proliferation and migration. In this study, we revealed a novel biological function of UCA1, which was different from that reported by previous studies, was responsible for maintaining the low-tumorigenic, nonmetastatic phenotypes in primary prostate epithelial cells. UCA1 could stabilize E-cadherin protein by preventing the interaction between E-cadherin and its E3 ligase MDM2, which suppressed MDM2-mediated ubiquitination and degradation of E-cadherin. In addition, we also found that UCA1 acted as a sponge of miR-296-3p, which targeted E-cadherin gene CDH1 messenger RNA at the posttranscription level. Taken together, these findings demonstrated that UCA1 had a new important role in effectively keeping E-cadherin at a high level through a dual mechanism, which maintained primary prostate cancer cells at the low-tumorigenic and nonmetastatic status.


Assuntos
Antígenos CD/metabolismo , Biomarcadores Tumorais/metabolismo , Caderinas/metabolismo , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias da Próstata/patologia , RNA Longo não Codificante/genética , Animais , Antígenos CD/genética , Apoptose , Biomarcadores Tumorais/genética , Caderinas/genética , Proliferação de Células , Humanos , Masculino , Camundongos , Camundongos SCID , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Cell Death Dis ; 11(3): 187, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179733

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is associated with metaplastic changes in the pancreas but the transcriptional program underlying these changes is incompletely understood. The zinc finger transcription factor, PRDM3, is lowly expressed in normal pancreatic acini and its expression increases during tumorigenesis. Although PRDM3 promotes proliferation and migration of PDAC cell lines, the role of PRDM3 during tumor initiation from pancreatic acinar cells in vivo is unclear. In this study, we showed that high levels of PRDM3 expression in human pancreas was associated with pancreatitis, and well-differentiated but not poorly differentiated carcinoma. We examined PRDM3 function in pancreatic acinar cells during tumor formation and pancreatitis by inactivating Prdm3 using a conditional allele (Ptf1aCreER;Prdm3flox/flox mice) in the context of oncogenic Kras expression and supraphysiological cerulein injections, respectively. In Prdm3-deficient mice, KrasG12D-driven preneoplastic lesions were more abundant and progressed to high-grade precancerous lesions more rapidly. This is consistent with our observations that low levels of PRDM3 in human PDAC was correlated significantly with poorer survival in patient. Moreover, loss of Prdm3 in acinar cells elevated exocrine injury, enhanced immune cell activation and infiltration, and greatly increased acinar-to-ductal cell reprogramming upon cerulein-induced pancreatitis. Whole transcriptome analyses of Prdm3 knockout acini revealed that pathways involved in inflammatory response and Hif-1 signaling were significantly upregulated in Prdm3-depleted acinar cells. Taken together, our results suggest that Prdm3 favors the maintenance of acinar cell homeostasis through modulation of their response to inflammation and oncogenic Kras activation, and thus plays a previously unexpected suppressive role during PDAC initiation.


Assuntos
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Proteína do Locus do Complexo MDS1 e EVI1/metabolismo , Pancreatite/genética , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Pessoa de Meia-Idade
9.
Epigenetics Chromatin ; 12(1): 32, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164154

RESUMO

BACKGROUND: TET-mediated oxidation of 5-mC participates in both passive and active DNA demethylation, which exerts a significant influence on diverse biological processes. Mass spectrometry has identified multiple phosphorylation sites of TET2. However, the functions of these phosphosites and their corresponding kinases are mostly unknown. RESULTS: Here, we showed that AMP-activated protein kinase (AMPK) phosphorylates murine TET2 at the serine residue 97 (S97), and the phosphorylation enhances TET2 stability through promoting its binding to 14-3-3ß. AMPK ablation resulted in decreased global 5-hmC levels at the myotube stages, severe differentiation defects of C2C12 cells and significantly, total loss of expression of Pax7. Genome-wide analyses revealed increased DNA methylation at genic and enhancer regions of AMPK-null myoblasts and myotubes. Using CRISPR/Cas9 technology, we showed that a novel enhancer, which is hypermethylated in AMPK-null cells, regulates Pax7 expression. The phospho-mimicking mutant, TET2-S97E, could partly rescue the differentiation defect in AMPK-ablated C2C12 cells. CONCLUSIONS: Together, our data demonstrated that AMPK is a critical regulator of myogenesis, partly through phosphorylating TET2.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas de Ligação a DNA/metabolismo , Desenvolvimento Muscular/fisiologia , Músculos/citologia , Músculos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas 14-3-3/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Diferenciação Celular/genética , Metilação de DNA , Proteínas de Ligação a DNA/genética , Dioxigenases , Técnicas de Inativação de Genes , Estudo de Associação Genômica Ampla , Células HEK293 , Humanos , Camundongos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/citologia , Mioblastos/metabolismo , Fator de Transcrição PAX7/biossíntese , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas/genética
10.
Oncogene ; 38(9): 1410-1431, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30305728

RESUMO

Argonaute2 (AGO2) is an effector of small RNA mediated gene silencing. Increasing evidence show that post-translational modifications of AGO2 can change miRNA activity at specific or global levels. Among the six mature miRNAs that are encoded by miR-17-92, miR-19b1 is the most powerful to exert the oncogenic properties of the entire cluster. Here we identify that AGO2 can be acetylated by P300/CBP and deacetylated by HDAC7, and that acetylation occurs at three sites K720, K493, and K355. Mutation of K493R/K720R, but not K355R at AGO2, inhibits miR-19b biogenesis. We demonstrate that acetylation of AGO2 specifically increases its recruiting pre-miR-19b1 to form the miPDC (miRNA precursor deposit complex), thereby to enhance miR-19b maturation. The motif UGUGUG in the terminal-loop of pre-miR-19b1, as a specific processing feature that is recognized and bound by acetylated AGO2, is essential for the assembly of miRISC (miRNA-induced silencing complex) loading complex. Analyses on public clinical data, xenograft mouse models, and IHC and ISH staining of lung cancer tissues, further confirm that the high levels of both AGO2 acetylation and miR-19b correlate with poor prognosis in lung cancer patients. Our finding reveals a novel function of AGO2 acetylation in increasing oncogenic miR-19b biogenesis and suggests that modulation of AGO2 acetylation has potential clinical implications.


Assuntos
Proteínas Argonautas/genética , Carcinogênese/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Histona Desacetilases/genética , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto , Fatores de Transcrição de p300-CBP/genética
11.
Epigenetics Chromatin ; 11(1): 58, 2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30290828

RESUMO

Since the discovery of methylcytosine oxidase ten-eleven translocation (TET) proteins, we have witnessed an exponential increase in studies examining their roles in epigenetic regulation. TET family proteins catalyze the sequential oxidation of 5-methylcytosine (5mC) to oxidized methylcytosines including 5-hydroxymethylcytosine (5hmC), 5-formylcytosine, and 5-carboxylcytosine. TETs contribute to the regulation of lineage-specific gene expression via modulating DNA 5mC/5hmC balances at the proximal and distal regulatory elements of cell identity genes, and therefore enhance chromatin accessibility and gene transcription. Emerging evidence suggests that TET dioxygenases participate in the establishment and/or maintenance of hypomethylated bivalent domains at multiple differentiation-associated genes, and thus ensure developmental plasticity. Here, we review the current state of knowledge concerning TET family proteins, DNA hydroxymethylation, their distribution, and function in endoderm, mesoderm, and neuroectoderm specification. We will summarize the evidence pertaining to their crucial regulatory roles in lineage commitment and development.


Assuntos
Diferenciação Celular , Metilação de DNA , Dioxigenases/metabolismo , Animais , Linhagem da Célula , Dioxigenases/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos
12.
Nucleic Acids Res ; 46(6): 2883-2900, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29394393

RESUMO

Dynamic changes in DNA methylation and demethylation reprogram transcriptional outputs to instruct lineage specification during development. Here, we applied an integrative epigenomic approach to unveil DNA (hydroxy)methylation dynamics representing major endodermal lineage intermediates during pancreatic differentiation of human embryonic stem cells (hESCs). We found that 5-hydroxymethylcytosine (5hmC) marks genomic regions to be demethylated in the descendent lineage, thus reshaping the DNA methylation landscapes during pancreatic lineage progression. DNA hydroxymethylation is positively correlated with enhancer activities and chromatin accessibility, as well as the selective binding of lineage-specific pioneer transcription factors, during pancreatic differentiation. We further discovered enrichment of hydroxymethylated regions (termed '5hmC-rim') at the boundaries of large hypomethylated functional genomic regions, including super-enhancer, DNA methylation canyon and broad-H3K4me3 peaks. We speculate that '5hmC-rim' might safeguard low levels of cytosine methylation at these regions. Our comprehensive analysis highlights the importance of dynamic changes of epigenetic landscapes in driving pancreatic differentiation of hESC.


Assuntos
Diferenciação Celular/genética , Metilação de DNA , Endoderma/citologia , Células-Tronco Embrionárias Humanas/citologia , Pâncreas/citologia , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Linhagem Celular , Linhagem da Célula/genética , Endoderma/metabolismo , Epigênese Genética , Epigenômica , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Embrionárias Humanas/metabolismo , Humanos
13.
Biomaterials ; 139: 39-55, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28582717

RESUMO

The biomaterials-host interaction is a dynamic process in which macrophages play a vital role of regulation. Depending on the biochemical signals they sense, these highly plastic cells can mediate the immune response against the implanted scaffolds and/or exert regenerative potency to varying extent. Designing appropriate 'exterior signals' for scaffolds may exploit the power of endogenous macrophages to aid the regeneration of engineered tissues. To realise this goal, this study devised an injectable, instantaneously-solidifying coating material (acBSP) based on a unique, macrophage-affinitive glucomannan polysaccharide. Coating of three-dimensional hydrogel constructs with acBSP was rapid, neat and complete, requiring neither chemical reactions nor harsh conditions. Comprehensive in vitro analyses indicated that acBSP efficiently facilitated the adhesion and activation of macrophages and notably induced the macrophages to express pro-osteogenic/-angiogenic genes. Further in vivo assessment of acBSP-coated, mesenchymal stem cells-laden hydrogels in a murine dorsal subcutaneous pocket model demonstrated efficient macrophage activation, desirable scaffold-tissue integration and improved osteogenic differentiation in the delivered cells. In summary, by activating macrophages into a pro-osteogenic phenotype, the acBSP coating has demonstrated its competency as an innovative, open and efficacious platform to harness the power of host immunity for enhancing the regenerative performance of engineered tissue constructs.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Hidrogéis/farmacologia , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Mananas/farmacologia , Células-Tronco Mesenquimais/citologia , Osteogênese , Acetilação , Análise de Variância , Indutores da Angiogênese/química , Indutores da Angiogênese/farmacologia , Animais , Diferenciação Celular , Materiais Revestidos Biocompatíveis/química , Hidrogéis/química , Imunidade Inata/genética , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Mananas/química , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Osteogênese/efeitos dos fármacos , Receptores de Superfície Celular/metabolismo , Medicina Regenerativa , Engenharia Tecidual , Alicerces Teciduais/química , Transcriptoma/imunologia
14.
Eur J Pharm Sci ; 110: 62-69, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28554668

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of tumor amongst all human cancers due to late diagnosis and resistant to treatment with chemotherapy and radiation. Preclinical and clinical studies have revealed that ErbB family for example epidermal growth factor receptor (EGFR) is a validated molecular target for pancreatic cancer prevention and therapy. The ErbB signaling cascade is regulated by a member of the ADAM (a disintegrin and metalloprotease) family, namely ADAM17, by enzymatic cleavage of precursor ligands into soluble cytokines and growth factors. Mouse genetic studies have demonstrated that ADAM17 is required for PDAC development. In this study, we evaluated the anti-tumor effects of A9(B8) IgG - the first specific 'human and mouse cross-reactive' ADAM17 inhibitory antibody on pancreatic malignant transformation. We found that inhibition of ADAM17 with A9(B8) IgG efficiently suppressed the shedding of ADAM17 substrates both in vivo and in vitro. Furthermore, we demonstrated that administration of A9(B8) IgG significantly suppressed motility in human pancreatic cancer cells and also significantly delayed tumorigenesis in the Pdx1Cre;KrasG12D;Trp53fl/+PDAC mouse model. Inhibition of ADAM17 with A9(B8) IgG particularly affected the progression of pre-invasive pancreatic lesions to advanced PDAC in mice. Taken together, the preclinical data presented here will provide a starting point for clinical applications of ADAM17 targeted therapy.


Assuntos
Proteína ADAM17/imunologia , Anticorpos/farmacologia , Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Anticorpos/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinogênese/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Transdução de Sinais
15.
Cell Rep ; 13(2): 326-36, 2015 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-26440894

RESUMO

The generation of pancreas, liver, and intestine from a common pool of progenitors in the foregut endoderm requires the establishment of organ boundaries. How dorsal foregut progenitors activate pancreatic genes and evade the intestinal lineage choice remains unclear. Here, we identify Pdx1 and Sox9 as cooperative inducers of a gene regulatory network that distinguishes the pancreatic from the intestinal lineage. Genetic studies demonstrate dual and cooperative functions for Pdx1 and Sox9 in pancreatic lineage induction and repression of the intestinal lineage choice. Pdx1 and Sox9 bind to regulatory sequences near pancreatic and intestinal differentiation genes and jointly regulate their expression, revealing direct cooperative roles for Pdx1 and Sox9 in gene activation and repression. Our study identifies Pdx1 and Sox9 as important regulators of a transcription factor network that initiates pancreatic fate and sheds light on the gene regulatory circuitry that governs the development of distinct organs from multi-lineage-competent foregut progenitors.


Assuntos
Linhagem da Célula , Células-Tronco Embrionárias/metabolismo , Redes Reguladoras de Genes , Proteínas de Homeodomínio/genética , Intestinos/citologia , Fatores de Transcrição SOX9/genética , Transativadores/genética , Animais , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Pâncreas/citologia , Pâncreas/metabolismo , Fatores de Transcrição SOX9/metabolismo , Transativadores/metabolismo , Ativação Transcricional
16.
Cell Stem Cell ; 16(4): 386-99, 2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25842977

RESUMO

Embryonic development relies on the capacity of progenitor cells to appropriately respond to inductive cues, a cellular property known as developmental competence. Here, we report that epigenetic priming of enhancers signifies developmental competence during endodermal lineage diversification. Chromatin mapping during pancreatic and hepatic differentiation of human embryonic stem cells revealed the en masse acquisition of a poised chromatin state at enhancers specific to endoderm-derived cell lineages in gut tube intermediates. Experimentally, the acquisition of this poised enhancer state predicts the ability of endodermal intermediates to respond to inductive signals. Furthermore, these enhancers are first recognized by the pioneer transcription factors FOXA1 and FOXA2 when competence is acquired, while subsequent recruitment of lineage-inductive transcription factors, such as PDX1, leads to enhancer and target gene activation. Together, our results identify the acquisition of a poised chromatin state at enhancers as a mechanism by which progenitor cells acquire developmental competence.


Assuntos
Células-Tronco Embrionárias/fisiologia , Endoderma/fisiologia , Elementos Facilitadores Genéticos/genética , Gástrula/fisiologia , Pâncreas/fisiologia , Biomarcadores/metabolismo , Diferenciação Celular/genética , Linhagem Celular , Linhagem da Célula/genética , Montagem e Desmontagem da Cromatina , Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Histonas/genética , Histonas/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Especificidade de Órgãos/genética , RNA Interferente Pequeno/genética , Transativadores/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-25644779

RESUMO

The development of the pancreas and determination of endocrine cell fate are controlled by a highly complex interplay of signaling events and transcriptional networks. It is now known that an interconnected epigenetic program is also required to drive these processes. Recent studies using genome-wide approaches have implicated epigenetic regulators, such as DNA and histone-modifying enzymes and noncoding RNAs, to play critical roles in pancreas development and the maintenance of cell identity and function. Furthermore, genome-wide analyses have implicated epigenetic changes as a casual factor in the pathogenesis of diabetes. In the future, genomic approaches to further our understanding of the role of epigenetics in endocrine cell development and function will be useful for devising strategies to produce or manipulate ß-cells for therapies of diabetes.


Assuntos
Diabetes Mellitus/fisiopatologia , Epigênese Genética/fisiologia , Redes Reguladoras de Genes/fisiologia , Células Secretoras de Insulina/metabolismo , Pâncreas/crescimento & desenvolvimento , Proteoma/metabolismo , Animais , Diabetes Mellitus/patologia , Humanos , Células Secretoras de Insulina/citologia , Modelos Genéticos , Biologia de Sistemas/métodos , Transcrição Gênica/fisiologia
18.
Cell Stem Cell ; 12(2): 224-37, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23318056

RESUMO

Embryonic development is characterized by dynamic changes in gene expression, yet the role of chromatin remodeling in these cellular transitions remains elusive. To address this question, we profiled the transcriptome and select chromatin modifications at defined stages during pancreatic endocrine differentiation of human embryonic stem cells. We identify removal of Polycomb group (PcG)-mediated repression on stage-specific genes as a key mechanism for the induction of developmental regulators. Furthermore, we discover that silencing of transitory genes during lineage progression associates with reinstatement of PcG-dependent repression. Significantly, in vivo- but not in vitro-differentiated endocrine cells exhibit close similarity to primary human islets in regard to transcriptome and chromatin structure. We further demonstrate that endocrine cells produced in vitro do not fully eliminate PcG-mediated repression on endocrine-specific genes, probably contributing to their malfunction. These studies reveal dynamic chromatin remodeling during developmental lineage progression and identify possible strategies for improving cell differentiation in culture.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Células-Tronco Embrionárias/citologia , Pâncreas/citologia , Proteínas do Grupo Polycomb/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Montagem e Desmontagem da Cromatina/genética , Células-Tronco Embrionárias/metabolismo , Células Endócrinas/citologia , Células Endócrinas/metabolismo , Endoderma/citologia , Endoderma/metabolismo , Humanos , Camundongos , Proteínas do Grupo Polycomb/genética
19.
PLoS One ; 7(12): e52181, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23251699

RESUMO

The peptide hormone Urocortin 3 (Ucn 3) is abundantly and exclusively expressed in mouse pancreatic beta cells where it regulates insulin secretion. Here we demonstrate that Ucn 3 first appears at embryonic day (E) 17.5 and, from approximately postnatal day (p) 7 and onwards throughout adult life, becomes a unifying and exclusive feature of mouse beta cells. These observations identify Ucn 3 as a potential beta cell maturation marker. To determine whether Ucn 3 is similarly restricted to beta cells in humans, we conducted comprehensive immunohistochemistry and gene expression experiments on macaque and human pancreas and sorted primary human islet cells. This revealed that Ucn 3 is not restricted to the beta cell lineage in primates, but is also expressed in alpha cells. To substantiate these findings, we analyzed human embryonic stem cell (hESC)-derived pancreatic endoderm that differentiates into mature endocrine cells upon engraftment in mice. Ucn 3 expression in hESC-derived grafts increased robustly upon differentiation into mature endocrine cells and localized to both alpha and beta cells. Collectively, these observations confirm that Ucn 3 is expressed in adult beta cells in both mouse and human and appears late in beta cell differentiation. Expression of Pdx1, Nkx6.1 and PC1/3 in hESC-derived Ucn 3(+) beta cells supports this. However, the expression of Ucn 3 in primary and hESC-derived alpha cells demonstrates that human Ucn 3 is not exclusive to the beta cell lineage but is a general marker for both the alpha and beta cell lineages. Ucn 3(+) hESC-derived alpha cells do not express Nkx6.1, Pdx1 or PC1/3 in agreement with the presence of a separate population of Ucn 3(+) alpha cells. Our study highlights important species differences in Ucn 3 expression, which have implications for its utility as a marker to identify mature beta cells in (re)programming strategies.


Assuntos
Células-Tronco Embrionárias/metabolismo , Células Secretoras de Glucagon/metabolismo , Células Secretoras de Insulina/metabolismo , Urocortinas/metabolismo , Animais , Diferenciação Celular/genética , Linhagem da Célula , Células-Tronco Embrionárias/citologia , Expressão Gênica , Células Secretoras de Glucagon/citologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica/métodos , Células Secretoras de Insulina/citologia , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Camundongos , Transativadores/genética , Transativadores/metabolismo , Urocortinas/genética
20.
Cell Metab ; 16(4): 435-48, 2012 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-23040067

RESUMO

A significant portion of the genome is transcribed as long noncoding RNAs (lncRNAs), several of which are known to control gene expression. The repertoire and regulation of lncRNAs in disease-relevant tissues, however, has not been systematically explored. We report a comprehensive strand-specific transcriptome map of human pancreatic islets and ß cells, and uncover >1100 intergenic and antisense islet-cell lncRNA genes. We find islet lncRNAs that are dynamically regulated and show that they are an integral component of the ß cell differentiation and maturation program. We sequenced the mouse islet transcriptome and identify lncRNA orthologs that are regulated like their human counterparts. Depletion of HI-LNC25, a ß cell-specific lncRNA, downregulated GLIS3 mRNA, thus exemplifying a gene regulatory function of islet lncRNAs. Finally, selected islet lncRNAs were dysregulated in type 2 diabetes or mapped to genetic loci underlying diabetes susceptibility. These findings reveal a new class of islet-cell genes relevant to ß cell programming and diabetes pathophysiology.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Cromatina/química , Cromatina/metabolismo , Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 2/patologia , Regulação para Baixo , Perfilação da Expressão Gênica , Loci Gênicos , Humanos , Camundongos , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transativadores/genética , Transativadores/metabolismo
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