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1.
Gut ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38754953

RESUMO

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) has limited therapeutic options, particularly with immune checkpoint inhibitors. Highly chemoresistant 'stem-like' cells, known as cancer stem cells (CSCs), are implicated in PDAC aggressiveness. Thus, comprehending how this subset of cells evades the immune system is crucial for advancing novel therapies. DESIGN: We used the KPC mouse model (LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre) and primary tumour cell lines to investigate putative CSC populations. Transcriptomic analyses were conducted to pinpoint new genes involved in immune evasion. Overexpressing and knockout cell lines were established with lentiviral vectors. Subsequent in vitro coculture assays, in vivo mouse and zebrafish tumorigenesis studies, and in silico database approaches were performed. RESULTS: Using the KPC mouse model, we functionally confirmed a population of cells marked by EpCAM, Sca-1 and CD133 as authentic CSCs and investigated their transcriptional profile. Immune evasion signatures/genes, notably the gene peptidoglycan recognition protein 1 (PGLYRP1), were significantly overexpressed in these CSCs. Modulating PGLYRP1 impacted CSC immune evasion, affecting their resistance to macrophage-mediated and T-cell-mediated killing and their tumourigenesis in immunocompetent mice. Mechanistically, tumour necrosis factor alpha (TNFα)-regulated PGLYRP1 expression interferes with the immune tumour microenvironment (TME) landscape, promoting myeloid cell-derived immunosuppression and activated T-cell death. Importantly, these findings were not only replicated in human models, but clinically, secreted PGLYRP1 levels were significantly elevated in patients with PDAC. CONCLUSIONS: This study establishes PGLYRP1 as a novel CSC-associated marker crucial for immune evasion, particularly against macrophage phagocytosis and T-cell killing, presenting it as a promising target for PDAC immunotherapy.

2.
Nature ; 554(7693): 533-537, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29443959

RESUMO

Chronic inflammation increases the risk of developing one of several types of cancer. Inflammatory responses are currently thought to be controlled by mechanisms that rely on transcriptional networks that are distinct from those involved in cell differentiation. The orphan nuclear receptor NR5A2 participates in a wide variety of processes, including cholesterol and glucose metabolism in the liver, resolution of endoplasmic reticulum stress, intestinal glucocorticoid production, pancreatic development and acinar differentiation. In genome-wide association studies, single nucleotide polymorphisms in the vicinity of NR5A2 have previously been associated with the risk of pancreatic adenocarcinoma. In mice, Nr5a2 heterozygosity sensitizes the pancreas to damage, impairs regeneration and cooperates with mutant Kras in tumour progression. Here, using a global transcriptomic analysis, we describe an epithelial-cell-autonomous basal pre-inflammatory state in the pancreas of Nr5a2+/- mice that is reminiscent of the early stages of pancreatitis-induced inflammation and is conserved in histologically normal human pancreases with reduced expression of NR5A2 mRNA. In Nr5a2+/-mice, NR5A2 undergoes a marked transcriptional switch, relocating from differentiation-specific to inflammatory genes and thereby promoting gene transcription that is dependent on the AP-1 transcription factor. Pancreatic deletion of Jun rescues the pre-inflammatory phenotype, as well as binding of NR5A2 to inflammatory gene promoters and the defective regenerative response to damage. These findings support the notion that, in the pancreas, the transcriptional networks involved in differentiation-specific functions also suppress inflammatory programmes. Under conditions of genetic or environmental constraint, these networks can be subverted to foster inflammation.


Assuntos
Diferenciação Celular/genética , Regulação da Expressão Gênica , Inflamação/genética , Pâncreas/metabolismo , Pâncreas/patologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Transcriptoma , Células Acinares/metabolismo , Células Acinares/patologia , Animais , Cromatina/genética , Cromatina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Redes Reguladoras de Genes/genética , Genes jun/genética , Heterozigoto , Humanos , Camundongos , Especificidade de Órgãos/genética , Pancreatite/genética , Regiões Promotoras Genéticas/genética , Receptores Citoplasmáticos e Nucleares/deficiência , Receptores Citoplasmáticos e Nucleares/genética , Fator de Transcrição AP-1/metabolismo
3.
Int J Mol Sci ; 25(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38791271

RESUMO

Phenolic compounds from a hydroalcoholic extract of wet olive pomace were purified and concentrated by an integrated membrane process in organic media. First, UF010104 (Solsep BV) and UP005 (Microdyn Nadir) membranes were tested to be implemented in the ultrafiltration stage, with the aim of purifying the extract and obtaining a permeate enriched in phenolic compounds. Despite the high flux observed with the UF010104 membrane (20.4 ± 0.7 L·h-1·m-2, at 2 bar), the UP005 membrane was selected because of a more suitable selectivity. Even though some secoiridoids were rejected, the permeate stream obtained with this membrane contained high concentrations of valuable simple phenols and phenolic acids, whereas sugars and macromolecules were retained. Then, the ultrafiltration permeate was subjected to a nanofiltration step employing an NF270 membrane (DuPont) for a further purification and fractionation of the phenolic compounds. The permeate flux was 50.2 ± 0.2 L·h-1·m-2, working at 15 bar. Hydroxytyrosol and some phenolic acids (such as vanillic acid, caffeic acid, and ferulic acid) were recovered in the permeate, which was later concentrated by reverse osmosis employing an NF90 membrane. The permeate flux obtained with this membrane was 15.3 ± 0.3 L·h-1·m-2. The concentrated phenolic mixture that was obtained may have important applications as a powerful antioxidant and for the prevention of diabetes and neurodegenerative diseases.


Assuntos
Membranas Artificiais , Olea , Fenóis , Ultrafiltração , Olea/química , Ultrafiltração/métodos , Fenóis/isolamento & purificação , Fenóis/química , Fenóis/análise , Osmose , Solventes/química , Extratos Vegetais/química
4.
Xenobiotica ; 52(1): 65-78, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34761729

RESUMO

MAK683 (N-((5-fluoro-2,3-dihydrobenzofuran-4-yl)methyl)-8-(2-methylpyridin-3-yl)-[1,2,4]triazolo[4,3-c]pyrimidin-5-amine) is a potent and orally bioavailable EED inhibitor for the potential treatment in oncology. Pharmacokinetics (PK) in preclinical species are characterised by low to moderate plasma clearances, high oral exposure, and moderate to high oral bioavailability at the dose of 1-2 mg/kg.A species comparison of the metabolic pathways of MAK683 has been made using [14C]MAK683 incubations with liver microsomes and hepatocytes from rat, dog, cynomolgus monkey, and human. Overall, the in vitro hepatic metabolism pathway of MAK683 in all five species was very complex. A total of 60 metabolites with 19 metabolites >1.5% of the total integrated area in the radiochromatogram of at least one species were identified in five species (rat, mouse, dog, monkey, and human).The primary in vitro hepatic oxidative metabolism pathway identified in humans involved 2-hydroxylation of the dihydrofuran ring to form alcohol (M28), which was in a chemical equilibrium favouring the formation of its aldehyde form. The aldehyde was then oxidised to the carboxylic acid metabolite (M26) or reduced to the O-hydroxyethylphenol (M29). N-dealkylation (M1), 3-hydroxylation of the dihydrofuran ring (M27), N-oxidation of the pyridine moiety (M53), and sulphate conjugation of M28 to form M19 were also important biotransformation pathways in human hepatocytes. The above major human hepatic metabolic pathways were also observed across the animal species (rat, mouse, dog, and monkey) mostly providing precursors for the formation of other metabolites via further oxygenation, glucuronidation, and sulphation pathways.No human-specific metabolites were observed. In addition, in vivo biotransformation was also conducted in bile-duct cannulated (BDC) rat. The metabolism in BDC rat was similar to those observed the in vitro hepatocytes.


Assuntos
Ectoderma , Neoplasias , Animais , Cães , Hepatócitos/metabolismo , Macaca fascicularis , Camundongos , Microssomos Hepáticos/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Ratos
5.
Int J Mol Sci ; 22(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669845

RESUMO

Pancreatic ductal adenocarcinoma (PDA) is the most common cancer of the exocrine pancreas and probably the tumor that has benefited the least from clinical progress in the last three decades. A consensus has been reached regarding the histologic classification of the ductal preneoplastic lesions (pancreatic intra-epithelial neoplasia-PanIN) and the molecular alterations associated with them. Mutations in KRAS and inactivation of CDKN2A, SMAD4 and TP53 are among the most prevalent alterations. Next generation sequencing studies are providing a broad picture of the enormous heterogeneity in this tumor type, describing new mutations less prevalent. These studies have also allowed the characterization of different subtypes with prognostic value. However, all this knowledge has not been translated into a clinical progress. Effective preventive and early diagnostic strategies are essential to improve the survival rates. The main challenge is, indeed, to identify new effective drugs. Despite many years of research and its limited success, gemcitabine is still the first line treatment of PDA. New drug combinations and new concepts to improve drug delivery into the tumor, as well as the development of preclinical predictive assays, are being explored and provide optimism and prospects for better therapies.


Assuntos
Neoplasias Pancreáticas/genética , Pesquisa Translacional Biomédica , Epigênese Genética , Heterogeneidade Genética , Predisposição Genética para Doença , Humanos , Terapia de Alvo Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia
6.
Molecules ; 26(17)2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34500809

RESUMO

We demonstrate a novel structure based on smart carbon nanocomposites intended for fabricating laser-triggered drug delivery devices (DDDs). The performance of the devices relies on nanocomposites' photothermal effects that are based on polydimethylsiloxane (PDMS) with carbon nanoparticles (CNPs). Upon evaluating the main features of the nanocomposites through physicochemical and photomechanical characterizations, we identified the main photomechanical features to be considered for selecting a nanocomposite for the DDDs. The capabilities of the PDMS/CNPs prototypes for drug delivery were tested using rhodamine-B (Rh-B) as a marker solution, allowing for visualizing and quantifying the release of the marker contained within the device. Our results showed that the DDDs readily expel the Rh-B from the reservoir upon laser irradiation and the amount of released Rh-B depends on the exposure time. Additionally, we identified two main Rh-B release mechanisms, the first one is based on the device elastic deformation and the second one is based on bubble generation and its expansion into the device. Both mechanisms were further elucidated through numerical simulations and compared with the experimental results. These promising results demonstrate that an inexpensive nanocomposite such as PDMS/CNPs can serve as a foundation for novel DDDs with spatial and temporal release control through laser irradiation.


Assuntos
Portadores de Fármacos/química , Nanocompostos/química , Materiais Inteligentes/química , Carbono/química , Dimetilpolisiloxanos/química , Portadores de Fármacos/efeitos da radiação , Elasticidade , Lasers , Luz , Fenômenos Mecânicos , Nanocompostos/efeitos da radiação , Rodaminas/química , Materiais Inteligentes/efeitos da radiação
7.
Compr Rev Food Sci Food Saf ; 19(6): 3528-3573, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33337049

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are food contaminants whose presence in foodstuffs is especially alarming due to their carcinogenic character. These substances are highly lipophilic and thus, unsafe levels of these compounds have been found in edible fats and oils. Efficient methodologies to determine such molecules in lipidic matrixes are therefore essential. In this review, a detailed description of the analytical methods for the determination of PAHs in vegetable oils from the last 15 years has been provided. Particular emphasis has been placed on innovative sample treatments, which facilitate and shorten the pretreatment of the oils. Finally, results from recent investigations have been reviewed and studied in depth, in order to elucidate which PAHs are most commonly found in vegetable oils.


Assuntos
Óleos de Plantas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Carcinógenos/análise , Cromatografia Gasosa/métodos , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Hidrocarbonetos Policíclicos Aromáticos/química
8.
Gut ; 67(4): 707-718, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28159836

RESUMO

BACKGROUND AND AIMS: c-Myc is highly expressed in pancreatic multipotent progenitor cells (MPC) and in pancreatic cancer. The transition from MPC to unipotent acinar progenitors is associated with c-Myc downregulation; a role for c-Myc in this process, and its possible relationship to a role in cancer, has not been established. DESIGN: Using coimmunoprecipitation assays, we demonstrate that c-Myc and Ptf1a interact. Using reverse transcriptase qPCR, western blot and immunofluorescence, we show the erosion of the acinar programme. To analyse the genomic distribution of c-Myc and Ptf1a and the global transcriptomic profile, we used ChIP-seq and RNA-seq, respectively; validation was performed with ChIP-qPCR and RT-qPCR. Lineage-tracing experiments were used to follow the effect of c-Myc overexpression in preacinar cells on acinar differentiation. RESULTS: c-Myc binds and represses the transcriptional activity of Ptf1a. c-Myc overexpression in preacinar cells leads to a massive erosion of differentiation. In adult Ela1-Myc mice: (1) c-Myc binds to Ptf1a, and Tcf3 is downregulated; (2) Ptf1a and c-Myc display partially overlapping chromatin occupancy but do not bind the same E-boxes; (3) at the proximal promoter of genes coding for digestive enzymes, we find reduced PTF1 binding and increased levels of repressive chromatin marks and PRC2 complex components. Lineage tracing of committed acinar precursors reveals that c-Myc overexpression does not restore multipotency but allows the persistence of a preacinar-like cell population. In addition, mutant KRas can lead to c-Myc overexpression and acinar dysregulation. CONCLUSIONS: c-Myc repression during development is crucial for the maturation of preacinar cells, and c-Myc overexpression can contribute to pancreatic carcinogenesis through the induction of a dedifferentiated state.


Assuntos
Células Acinares/metabolismo , Regulação para Baixo/genética , Homeostase , Pâncreas/metabolismo , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Diferenciação Celular , Modelos Animais de Doenças , Homeostase/genética , Camundongos , Fatores de Transcrição/genética
10.
Gut ; 64(6): 937-47, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25037190

RESUMO

OBJECTIVE: Pancreatic acinar cell maturation is dependent on the activity of the pancreas transcription factor 1 (PTF1) complex. Induction of pancreatitis leads to MAP kinase activation and transient suppression of the acinar differentiation programme. We investigated the role of MAP kinase-interacting kinase 1 (Mnk1) in mouse exocrine pancreas development and in the response to secretagogue-induced pancreatitis. DESIGN: Mnk1 expression was analysed using immunohistochemistry, RT-qPCR and western blotting. Ptf1a binding to Mnk1 was assessed by chromatin immunoprecipitation and qPCR. Acute pancreatitis was induced in wild type and Mnk1(-/-) mice by 7 h intraperitoneal injections of caerulein. In vitro amylase secretion and trypsinogen activation were assessed using freshly isolated acinar cells. In vivo secretion was quantified by secretin-stimulated MRI. RESULTS: Mnk1 is expressed at the highest levels in pancreatic acinar cells and is a direct PTF1 target. Mnk1 is activated upon induction of pancreatitis and is indispensable for eIF4E phosphorylation. The pancreas of Mnk1(-/-) mice is histologically normal. Digestive enzyme content is significantly increased and c-Myc and Ccnd1 levels are reduced in Mnk1(-/-) mice. Upon induction of acute pancreatitis, Mnk1(-/-) mice show impaired eIF4E phosphorylation, activation of c-Myc and downregulation of zymogen content. Acinar cells show defective relocalisation of digestive enzymes, polarity defects and impaired secretory response in vitro and in vivo. CONCLUSIONS: Mnk1 is a novel pancreatic acinar cell-specific stress response kinase that regulates digestive enzyme abundance and eIF4E phosphorylation. It is required for the physiological secretory response of acinar cells and for the homeostatic response to caerulein administration during acute pancreatitis.


Assuntos
Células Acinares/enzimologia , Pâncreas Exócrino/metabolismo , Pancreatite/metabolismo , Pancreatite/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Células Acinares/citologia , Amilases/metabolismo , Animais , Diferenciação Celular , Ceruletídeo , Colangiopancreatografia por Ressonância Magnética , Regulação para Baixo , Ativação Enzimática , Fator de Iniciação 4E em Eucariotos/metabolismo , Marcação de Genes , Resposta ao Choque Térmico/fisiologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Pancreatite/induzido quimicamente , Fosforilação , Fatores de Transcrição/metabolismo , Tripsinogênio/metabolismo
11.
Gastroenterology ; 147(4): 882-892.e8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24998203

RESUMO

BACKGROUND & AIMS: Development of pancreatic ductal adenocarcinoma (PDAC) involves activation of c-Ki-ras2 Kirsten rat sarcoma oncogene homolog (KRAS) signaling, but little is known about the roles of proteins that regulate the activity of oncogenic KRAS. We investigated the activities of proteins that interact with KRAS in PDAC cells. METHODS: We used mass spectrometry to demonstrate that heterogeneous nuclear ribonucleoproteins (HNRNP) A2 and B1 (encoded by the gene HNRNPA2B1) interact with KRAS G12V. We used co-immunoprecipitation analyses to study interactions between HNRNPA2B1 and KRAS in KRAS-dependent and KRAS-independent PDAC cell lines. We knocked down HNRNPA2B1 using small hairpin RNAs and measured viability, anchorage-independent proliferation, and growth of xenograft tumors in mice. We studied KRAS phosphorylation using the Phos-tag system. RESULTS: We found that interactions between HRNPA2B1 and KRAS correlated with KRAS-dependency of some human PDAC cell lines. Knock down of HNRNPA2B1 significantly reduced viability, anchorage-independent proliferation, and formation of xenograft tumors by KRAS-dependent PDAC cells. HNRNPA2B1 knock down also increased apoptosis of KRAS-dependent PDAC cells, inactivated c-akt murine thymoma oncogene homolog 1 signaling via mammalian target of rapamycin, and reduced interaction between KRAS and phosphatidylinositide 3-kinase. Interaction between HNRNPA2B1 and KRAS required KRAS phosphorylation at serine 181. CONCLUSIONS: In KRAS-dependent PDAC cell lines, HNRNPA2B1 interacts with and regulates the activity of KRAS G12V and G12D. HNRNPA2B1 is required for KRAS activation of c-akt murine thymoma oncogene homolog 1-mammalian target of rapamycin signaling, interaction with phosphatidylinositide 3-kinase, and PDAC cell survival and tumor formation in mice. HNRNPA2B1 might be a target for treatment of pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas ras/metabolismo , Animais , Apoptose , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HeLa , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Humanos , Camundongos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Interferência de RNA , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Transfecção , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/genética
13.
Biochem J ; 451(3): 395-405, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23339455

RESUMO

The PTF1 (pancreas transcription factor 1) complex is a master regulator of differentiation of acinar cells, responsible for the production of digestive enzymes. In the adult pancreas, PTF1 contains two pancreas-restricted transcription factors: Ptf1a and Rbpjl. PTF1 recruits P/CAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] which acetylates Ptf1a and enhances its transcriptional activity. Using yeast two-hybrid screening, we identified ICAT (inhibitor of ß-catenin and Tcf4) as a novel Ptf1a interactor. ICAT regulates the Wnt pathway and cell proliferation. We validated and mapped the ICAT-Ptf1a interaction in vitro and in vivo. We demonstrated that, following its overexpression in acinar tumour cells, ICAT regulates negatively PTF1 activity in vitro and in vivo. This effect was independent of ß-catenin and was mediated by direct binding to Ptf1a and displacement of P/CAF. ICAT also modulated the expression of Pdx1 and Sox9 in acinar tumour cells. ICAT overexpression reduced the interaction of Ptf1a with Rbpjl and P/CAF and impaired Ptf1a acetylation by P/CAF. ICAT did not affect the subcellular localization of Ptf1a. In human pancreas, ICAT displayed a cell-type-specific distribution; in acinar and endocrine cells, it was nuclear, whereas in ductal cells, it was cytoplasmic. In ductal adenocarcinomas, ICAT displayed mainly a nuclear or mixed distribution and the former was an independent marker of survival. ICAT regulates acinar differentiation and it does so through a novel Wnt pathway-independent mechanism that may contribute to pancreatic disease.


Assuntos
Células Acinares/metabolismo , Adenocarcinoma/genética , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Pâncreas Exócrino/metabolismo , Neoplasias Pancreáticas/genética , Fatores de Transcrição/genética , Células Acinares/patologia , Proteínas Adaptadoras de Transdução de Sinal , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Diferenciação Celular , Proliferação de Células , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Pessoa de Meia-Idade , Pâncreas Exócrino/patologia , Ductos Pancreáticos/metabolismo , Ductos Pancreáticos/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Ligação Proteica , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Análise de Sobrevida , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Via de Sinalização Wnt , beta Catenina/genética , beta Catenina/metabolismo , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismo
14.
Rev Invest Clin ; 66 Suppl 1: S100-10, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25264790

RESUMO

Complete rupture of the anterior cruciate ligament (ACL) is a common problem in orthopedics. At present, there are many techniques to reconstruct ligaments, which include the use of autografts, allografts, and, in some cases, artificial ligaments. The latter have not provided good results in the short, medium, and long term. The purpose of present study was to engineer functional biological tissue that could potentially be used to replace the knee ligaments by applying tissue engineering techniques and mechanical stimulation with a bioreactor, promoting cellular differentiation and matrix synthesis. In this preliminary study, the new tissue was characterized with mechanical tests and biological tests (viability and immunochemistry), comparing their behavior with that of the native tissue. Mechanical and biological tests proved that mechanical stimulation administered with a bioreactor maintains the ligament fibroblast phenotype and promotes synthesis of the extracellular matrix.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/cirurgia , Reatores Biológicos , Engenharia Tecidual/métodos , Animais , Lesões do Ligamento Cruzado Anterior , Diferenciação Celular/fisiologia , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Técnicas In Vitro , Suínos
15.
Polymers (Basel) ; 16(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38475257

RESUMO

The development of injectable hydrogels with natural biopolymers such as gelatin (Ge) and hyaluronic acid (Ha) is widely performed due to their biocompatibility and biodegradability. The combination of both polymers crosslinked with N-Ethyl-N'-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) can be used as an innovative dermal filler that stimulates fibroblast activity and increases skin elasticity and tightness. Thus, crosslinked Ge/Ha hydrogels with different concentrations of EDC were administered subcutaneously to test their efficacy in young and old rats. At higher EDC concentrations, the viscosity decreases while the particle size of the hydrogels increases. At all concentrations of EDC, amino and carboxyl groups are present. The histological analysis shows an acute inflammatory response, which disappears seven days after application. At one and three months post-treatment, no remains of the hydrogels are found, and the number of fibroblasts increases in all groups in comparison with the control. In addition, the elastic modulus of the skin increases after three months of treatment. Because EDC-crosslinked Ge/Ha hydrogels are biocompatible and induce increased skin tension, fibroblast proliferation, and de novo extracellular matrix production, we propose their use as a treatment to attenuate wrinkles and expression lines.

16.
Crit Rev Immunol ; 32(4): 321-34, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23237508

RESUMO

Since the discovery of the myc gene, few genes are likely to have such influence on biomedical research. The diversity of the biological functions regulated by this transcription factor and its impact in human health have attracted investigators from many different fields. The development of conditional knockout mouse models has allowed for the characterization of Myc-driven molecular mechanisms in primary cells in physiological and pathological conditions. In this review, we discuss some of the main functions and recent findings regarding c-Myc in in vivo B lymphocyte differentiation from early progenitors to terminally differentiated cells.


Assuntos
Linfócitos B/citologia , Linfócitos B/metabolismo , Diferenciação Celular , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Humanos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-myc/deficiência , Proteínas Proto-Oncogênicas c-myc/genética
17.
Membranes (Basel) ; 13(2)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36837622

RESUMO

Despite the environmental concerns raised every year by the generation of high volumes of wet olive pomace, it contains valuable phenolic compounds that are essential for the valorization of this by-product. In this work, an integrated process to recover phenolic compounds from wet olive pomace is proposed. It consists of ultrasound-assisted solid-liquid extraction, followed by ultrafiltration and nanofiltration. Several commercial membranes were studied at different operational conditions. The ultrafiltration stage allowed the purification of biophenols, which were obtained in the permeate stream. Regarding organic matter, satisfactory rejection values were obtained with both commercial UH030 and UP005 membranes (Microdyn Nadir), but the latter provided more efficient purification and higher values of permeate flux, above 18 L·h-1·m-2 at 2.5 bar and 1.5 m·s-1. Later, this permeate stream was concentrated by means of a nanofiltration process, obtaining polyphenol rejection values that surpassed 85% with the commercial NF270 membrane (DuPont), then achieving the concentration of the previously purified polyphenols.

18.
J Physiol Biochem ; 79(1): 179-192, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35102531

RESUMO

Pancreatic ductal adenocarcinoma (PDA) is a disease with a survival rate of 9%; this is due to its chemoresistance and the large tumour stroma that occupies most of the tumour mass. It is composed of a large number of cells of the immune system, such as Treg cells, tumour-associated macrophages (TAMs), myeloid suppressor cells (MDCs) and tumour-associated neutrophiles (TANs) that generate an immunosuppressive environment by the release of inflammatory cytokines. Moreover, cancer-associated fibroblast (CAFs) provide a protective coverage that would difficult the access of chemotherapy to the tumour. According to this, new therapies that could remodel this heterogeneous tumour microenvironment, such as adoptive T cell therapies (ACT), immune checkpoint inhibitors (ICI), and CD40 agonists, should be developed for targeting PDA. This review organizes the different cell populations found in the tumour stroma involved in tumour progression in addition to the different therapies that are being studied to counteract the tumour.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Microambiente Tumoral , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Linfócitos T CD8-Positivos , Neoplasias Pancreáticas
19.
Heliyon ; 9(8): e18953, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37609429

RESUMO

Melanoma is the most aggressive form of skin cancer and the leading cause of death from cutaneous tumors. Several studies have associated alterations in the TERT promoter region (pTERT) with gene overexpression, aggressiveness and poor prognosis of the disease. The aim of this study was to clarify the role of pTERT molecular status in paired samples of primary melanoma and metastasis using tissue and plasma to establish a correlation with disease progression and survival. A total of 88 FFPE tissue samples from 53 patients with advanced melanoma were analyzed. Of these, 35 had paired samples. We also examined cfDNA samples from plasma of 25 patients. We detected a good correlation between primary tumors and metastases in pTERT mutation and methylation status. We were also able to identify pTERT mutations in plasma samples that correlated with mutational status in tissue samples. Interestingly, the C250T mutation was associated with worse survival and higher TERT mRNA expression, compared to the other most common mutation: C228T. In addition, hyper-methylation of the promoter region seems to be related to the progression of pTERT wild type (WT) patients. These results suggest that TERT gene alterations plays an important role during tumor progression, with the detection of the C250T mutation in tissue and plasma as a potential biomarker of poor prognosis in patients with advanced melanoma.

20.
Biomolecules ; 12(6)2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35740959

RESUMO

Extremophilic microorganisms often produce novel bioactive compounds to survive under harsh environmental conditions. Exopolysaccharides (EPSs), a constitutive part of bacterial biofilm, are functional biopolymers that act as a protecting sheath to the extremophilic bacteria and are of high industrial value. In this study, we elucidate a new EPS produced by thermophilic Bacillus haynesii CamB6 from a slightly acidic (pH 5.82) Campanario hot spring (56.4 °C) located in the Central Andean Mountains of Chile. Physicochemical properties of the EPS were characterized by different techniques: Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), Atomic Force Microscopy (AFM), High-Performance Liquid Chromatography (HPLC), Gel permeation chromatography (GPC), Fourier Transform Infrared Spectroscopy (FTIR), 1D and 2D Nuclear Magnetic Resonance (NMR), and Thermogravimetric analysis (TGA). The EPS demonstrated amorphous surface roughness composed of evenly distributed macromolecular lumps. GPC and HPLC analysis showed that the EPS is a low molecular weight heteropolymer composed of mannose (66%), glucose (20%), and galactose (14%). FTIR analysis demonstrated the polysaccharide nature (-OH groups, Acetyl groups, and pyranosic ring structure) and the presence of different glycosidic linkages among sugar residues, which was further confirmed by NMR spectroscopic analyses. Moreover, D-mannose α-(1→2) and α-(1→4) linkages prevail in the CamB6 EPS structure. TGA revealed the high thermal stability (240 °C) of the polysaccharide. The functional properties of the EPS were evaluated for food industry applications, specifically as an antioxidant and for its emulsification, water-holding (WHC), oil-holding (OHC), and flocculation capacities. The results suggest that the study EPS can be a useful additive for the food-processing industry.


Assuntos
Bacillus , Polissacarídeos Bacterianos , Peso Molecular , Polissacarídeos Bacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier
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