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1.
Cell ; 142(2): 230-42, 2010 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-20655466

RESUMO

Human telomeres are protected from DNA damage by a nucleoprotein complex that includes the repeat-binding factor TRF2. Here, we report that TRF2 regulates the 5' exonuclease activity of its binding partner, Apollo, a member of the metallo-beta-lactamase family that is required for telomere integrity during S phase. TRF2 and Apollo also suppress damage to engineered interstitial telomere repeat tracts that were inserted far away from chromosome ends. Genetic data indicate that DNA topoisomerase 2alpha acts in the same pathway of telomere protection as TRF2 and Apollo. Moreover, TRF2, which binds preferentially to positively supercoiled DNA substrates, together with Apollo, negatively regulates the amount of TOP1, TOP2alpha, and TOP2beta at telomeres. Our data are consistent with a model in which TRF2 and Apollo relieve topological stress during telomere replication. Our work also suggests that cellular senescence may be caused by topological problems that occur during the replication of the inner portion of telomeres.


Assuntos
Antígenos de Neoplasias/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Replicação do DNA , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Telômero/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Senescência Celular , Dano ao DNA , Exodesoxirribonucleases , Humanos , Estrutura Terciária de Proteína
2.
N Engl J Med ; 382(9): 835-844, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32101665

RESUMO

Mutations in VHL, which encodes von Hippel-Lindau tumor suppressor (VHL), are associated with divergent diseases. We describe a patient with marked erythrocytosis and prominent mitochondrial alterations associated with a severe germline VHL deficiency due to homozygosity for a novel synonymous mutation (c.222C→A, p.V74V). The condition is characterized by early systemic onset and differs from Chuvash polycythemia (c.598C→T) in that it is associated with a strongly reduced growth rate, persistent hypoglycemia, and limited exercise capacity. We report changes in gene expression that reprogram carbohydrate and lipid metabolism, impair muscle mitochondrial respiratory function, and uncouple oxygen consumption from ATP production. Moreover, we identified unusual intermitochondrial connecting ducts. Our findings add unexpected information on the importance of the VHL-hypoxia-inducible factor (HIF) axis to human phenotypes. (Funded by Associazione Italiana Ricerca sul Cancro and others.).


Assuntos
Mutação em Linhagem Germinativa , Transtornos do Crescimento/genética , Hipoglicemia/genética , Fator 1 Induzível por Hipóxia/deficiência , Mitocôndrias/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Expressão Gênica , Crescimento/genética , Humanos , Masculino , Metaboloma/genética , Metaboloma/fisiologia , Síndrome , Adulto Jovem
3.
Cell Mol Life Sci ; 79(10): 536, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181557

RESUMO

Microgravity-induced bone loss is a major concern for space travelers. Ground-based microgravity simulators are crucial to study the effect of microgravity exposure on biological systems and to address the limitations posed by restricted access to real space. In this work, for the first time, we adopt a multidisciplinary approach to characterize the morphological, biochemical, and molecular changes underlying the response of human bone marrow stromal cells to long-term simulated microgravity exposure during osteogenic differentiation. Our results show that osteogenic differentiation is reduced while energy metabolism is promoted. We found novel proteins were dysregulated under simulated microgravity, including CSC1-like protein, involved in the mechanotransduction of pressure signals, and PTPN11, SLC44A1 and MME which are involved in osteoblast differentiation pathways and which may become the focus of future translational projects. The investigation of cell proteome highlighted how simulated microgravity affects a relatively low number of proteins compared to time and/or osteogenic factors and has allowed us to reconstruct a hypothetical pipeline for cell response to simulated microgravity. Further investigation focused on the application of nanomaterials may help to increase understanding of how to treat or minimize the effects of microgravity.


Assuntos
Células-Tronco Mesenquimais , Ausência de Peso , Antígenos CD , Células da Medula Óssea , Diferenciação Celular/fisiologia , Humanos , Mecanotransdução Celular , Proteínas de Transporte de Cátions Orgânicos , Osteogênese , Proteoma , Simulação de Ausência de Peso
4.
Int J Mol Sci ; 24(3)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36768427

RESUMO

Breast cancer is the second leading cause of cancer-related death in women in the world, and its management includes a combination of surgery, radiation therapy, chemotherapy, and immunotherapy, whose effectiveness depends largely, but not exclusively, on the molecular subtype (Luminal A, Luminal B, HER2+ and Triple Negative). All breast cancer subtypes are accompanied by peculiar and substantial changes in sphingolipid metabolism. Alterations in sphingolipid metabolite levels, such as ceramides, dihydroceramide, sphingosine, sphingosine-1-phosphate, and sphingomyelin, as well as in their biosynthetic and catabolic enzymatic pathways, have emerged as molecular mechanisms by which breast cancer cells grow, respond to or escape therapeutic interventions and could take on diagnostic and prognostic value. In this review, we summarize the current landscape around two main themes: 1. sphingolipid metabolites, enzymes and transport proteins that have been found dysregulated in human breast cancer cells and/or tissues; 2. sphingolipid-driven mechanisms that allow breast cancer cells to respond to or evade therapies. Having a complete picture of the impact of the sphingolipid metabolism in the development and progression of breast cancer may provide an effective means to improve and personalize treatments and reduce associated drug resistance.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Ceramidas/metabolismo , Esfingolipídeos/metabolismo , Esfingomielinas , Metabolismo dos Lipídeos
5.
Int J Mol Sci ; 23(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35409143

RESUMO

Telomeres are crucial structures that preserve genome stability. Their progressive erosion over numerous DNA duplications determines the senescence of cells and organisms. As telomere length homeostasis is critical for cancer development, nowadays, telomere maintenance mechanisms are established targets in cancer treatment. Besides telomere elongation, telomere dysfunction impinges on intracellular signaling pathways, in particular DNA damage signaling and repair, affecting cancer cell survival and proliferation. This review summarizes and discusses recent findings in anticancer drug development targeting different "telosome" components.


Assuntos
Neoplasias , Telomerase , Senescência Celular , DNA/metabolismo , Dano ao DNA , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Telomerase/genética , Telomerase/metabolismo , Telômero/genética , Telômero/metabolismo , Homeostase do Telômero
6.
Nucleic Acids Res ; 47(7): 3365-3382, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30698737

RESUMO

The telomeric protein TRF2 is overexpressed in several human malignancies and contributes to tumorigenesis even though the molecular mechanism is not completely understood. By using a high-throughput approach based on the multiplexed Luminex X-MAP technology, we demonstrated that TRF2 dramatically affects VEGF-A level in the secretome of cancer cells, promoting endothelial cell-differentiation and angiogenesis. The pro-angiogenic effect of TRF2 is independent from its role in telomere capping. Instead, TRF2 binding to a distal regulatory element promotes the expression of SULF2, an endoglucosamine-6-sulfatase that impairs the VEGF-A association to the plasma membrane by inducing post-synthetic modification of heparan sulfate proteoglycans (HSPGs). Finally, we addressed the clinical relevance of our findings showing that TRF2/SULF2 expression is a worse prognostic biomarker in colorectal cancer (CRC) patients.


Assuntos
Neoplasias do Colo/metabolismo , Sulfotransferases/genética , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/patologia , Proteoglicanas de Heparan Sulfato/química , Proteoglicanas de Heparan Sulfato/metabolismo , Heparina/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Metástase Neoplásica , Neovascularização Patológica , Sulfatases , Sulfotransferases/biossíntese , Proteína 2 de Ligação a Repetições Teloméricas/deficiência , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Nutr Neurosci ; 23(10): 779-790, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30545280

RESUMO

Introduction: Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by abnormal development of cognitive, social, and communicative skills. Although ASD aetiology and pathophysiology are still unclear, various nutritional factors have been investigated as potential risk factors for ASD development, including omega-3 polyunsaturated fatty acids (PUFAs) and vitamin D deficiency. In fact, both omega-3 PUFAs and vitamin D are important for brain development and function. Case report: Herein, we report the case of a 23-year-old young adult male with autism who was referred to our Unit due to a 12-month history of cyclic episodes of restlessness, agitation, irritability, oppositional and self-injurious behaviours. Laboratory tests documented a markedly altered omega-6/omega-3 balance, along with a vitamin D deficiency, as assessed by serum levels of 25-hydroxyvitamin D. Omega-3 and vitamin D co-supplementation was therefore started, with remarkable improvements in ASD symptoms throughout a 24-month follow-up period. A brief review of the literature for interventional studies evaluating the efficacy of omega-3 or vitamin D supplementation for the treatment of ASD-related symptoms is also provided. Conclusion: To our knowledge, this is the first case reporting remarkable beneficial effects on ASD symptoms deriving from omega-3 and vitamin D combination therapy. This case report suggests omega-3 and vitamin D co-supplementation as a potential safe-effective therapeutic strategy to treat core symptoms of ASD. However, larger studies are needed to evaluate the real efficacy of such therapeutic approach in a broader sample of ASD patients.


Assuntos
Transtorno do Espectro Autista/dietoterapia , Suplementos Nutricionais , Ácidos Graxos Ômega-3/administração & dosagem , Vitamina D/administração & dosagem , Vitaminas/administração & dosagem , Adulto , Transtorno do Espectro Autista/sangue , Ácidos Graxos Ômega-3/sangue , Humanos , Masculino , Resultado do Tratamento , Vitamina D/sangue , Adulto Jovem
8.
Int J Mol Sci ; 21(2)2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936443

RESUMO

Wound healing is a very complex process that allows organisms to survive injuries. It is strictly regulated by a number of biochemical and physical factors, mechanical forces included. Studying wound healing in space is interesting for two main reasons: (i) defining tools, procedures, and protocols to manage serious wounds and burns eventually occurring in future long-lasting space exploration missions, without the possibility of timely medical evacuation to Earth; (ii) understanding the role of gravity and mechanical factors in the healing process and scarring, thus contributing to unravelling the mechanisms underlying the switching between perfect regeneration and imperfect repair with scarring. In the study presented here, a new in vivo sutured wound healing model in the leech (Hirudo medicinalis) has been used to evaluate the effect of unloading conditions on the healing process and the effectiveness of platelet rich plasma (PRP) as a countermeasure. The results reveal that microgravity caused a healing delay and structural alterations in the repair tissue, which were prevented by PRP treatment. Moreover, investigating the effects of microgravity and PRP on an in vitro wound healing model, it was found that PRP is able to counteract the microgravity-induced impairment in fibroblast migration to the wound site. This could be one of the mechanisms underlying the effectiveness of PRP in preventing healing impairment in unloading conditions.


Assuntos
Modelos Biológicos , Plasma Rico em Plaquetas/metabolismo , Ausência de Peso , Cicatrização , Animais , Contagem de Células , Movimento Celular/genética , Colágeno/metabolismo , Elasticidade , Regulação da Expressão Gênica , Sanguessugas/fisiologia , Camundongos , Células NIH 3T3 , Fator A de Crescimento do Endotélio Vascular/metabolismo
9.
Nucleic Acids Res ; 45(4): 1820-1834, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-27923994

RESUMO

Telomere repeat binding factor 2 (TRF2) has been increasingly recognized to be involved in telomere maintenance and DNA damage response. Here, we show that TRF2 directly binds SIRT6 in a DNA independent manner and that this interaction is increased upon replication stress. Knockdown of SIRT6 up-regulates TRF2 protein levels and counteracts its down-regulation during DNA damage response, leading to cell survival. Moreover, we report that SIRT6 deactetylates in vivo the TRFH domain of TRF2, which in turn, is ubiquitylated in vivo activating the ubiquitin-dependent proteolysis. Notably, overexpression of the TRF2cT mutant failed to be stabilized by SIRT6 depletion, demonstrating that the TRFH domain is required for its post-transcriptional modification. Finally, we report an inverse correlation between SIRT6 and TRF2 protein expression levels in a cohort of colon rectal cancer patients. Taken together our findings describe TRF2 as a novel SIRT6 substrate and demonstrate that acetylation of TRF2 plays a crucial role in the regulation of TRF2 protein stability, thus providing a new route for modulating its expression level during oncogenesis and damage response.


Assuntos
Dano ao DNA , Sirtuínas/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Acetilação , Antineoplásicos Fitogênicos/farmacologia , Camptotecina/farmacologia , Linhagem Celular , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Humanos , Imuno-Histoquímica , Modelos Moleculares , Poli(ADP-Ribose) Polimerases/metabolismo , Ligação Proteica , Conformação Proteica , Estabilidade Proteica , Proteólise/efeitos dos fármacos , Proteínas Recombinantes de Fusão/metabolismo , Sirtuínas/química , Especificidade por Substrato , Proteína 2 de Ligação a Repetições Teloméricas/química , Proteína 2 de Ligação a Repetições Teloméricas/genética , Ubiquitinação
10.
Int J Mol Sci ; 20(15)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370282

RESUMO

Ischemic-reperfusion (I/R) injury induced a remodeling of protein and lipid homeostasis, under oxidative stress and inflammatory status. Starvation occurring during I/R is a condition leading to autophagy activation, which allows abnormal material clearance or amino acid, or both, and fatty acid (FA) recycling essential for survival. This study investigated the lipid reshaping, peroxidation, and related-signaling pathways, in rat brain endothelial cells (RBE4) subjected to 3 h of oxygen and glucose deprivation (OGD) and restoration of standard condition (I/R in vitro model). Lipids and proteins were analyzed after 1 or 24 h of oxygen and nutrient restoration. Together with the oxidative stress and inflammatory status, I/R injury induced a reshaping of neutral lipids and biogenesis of lipid droplets (LD) with excessive lipid storage. The increase of LC3-II/LC3-I ratio, an autophagy marker, and LC3 co-localization with LD suggest the activation of lipophagy machinery to counteract the cell engulfment. Lipophagy leads to cholesterol ester (CE) hydrolysis, increasing free cholesterol (FC) secretion, which occurred by specific transporters or unconventional exocytosis pathways, or both. Here, we propose that an unconventional spreading of FC and other lipid metabolites may influence the neurovascular unit (NVU) cells, contributing to Blood brain barrier (BBB) alteration or adaptation, or both, to the cumulative effects of several transient ischemia.


Assuntos
Autofagia/efeitos dos fármacos , Células Endoteliais/metabolismo , Glucose/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Oxigênio/farmacologia , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Hipóxia Celular , Linhagem Celular , Colesterol/metabolismo , Ésteres do Colesterol/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Expressão Gênica/efeitos dos fármacos , Glucose/deficiência , Gotículas Lipídicas/efeitos dos fármacos , Gotículas Lipídicas/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Biológicos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ratos , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia
11.
Gastroenterology ; 153(5): 1363-1377.e6, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28827082

RESUMO

BACKGROUND & AIMS: Alterations in signaling pathways that regulate resolution of inflammation (resolving pathways) contribute to pathogenesis of ulcerative colitis (UC). The resolution process is regulated by lipid mediators, such as those derived from the ω-3 docosahexaenoic acid (DHA), whose esterified form is transported by the major facilitator superfamily domain containing 2A (MFSD2A) through the endothelium of brain, retina, and placenta. We investigated if and how MFSD2A regulates lipid metabolism of gut endothelial cells to promote resolution of intestinal inflammation. METHODS: We performed lipidomic and functional analyses of MFSD2A in mucosal biopsies and primary human intestinal microvascular endothelial cells (HIMECs) isolated from surgical specimens from patients with active, resolving UC and healthy individuals without UC (controls). MFSD2A was knocked down in HIMECs with small hairpin RNAs or overexpressed from a lentiviral vector. Human circulating endothelial progenitor cells that overexpress MFSD2A were transferred to CD1 nude mice with dextran sodium sulfate-induced colitis, with or without oral administration of DHA. RESULTS: Colonic biopsies from patients with UC had reduced levels of inflammation-resolving DHA-derived epoxy metabolites compared to healthy colon tissues or tissues with resolution of inflammation. Production of these metabolites by HIMECs required MFSD2A, which is required for DHA retention and metabolism in the gut vasculature. In mice with colitis, transplanted endothelial progenitor cells that overexpressed MFSD2A not only localized to the inflamed mucosa but also restored the ability of the endothelium to resolve intestinal inflammation, compared with mice with colitis that did not receive MFSD2A-overexpressing endothelial progenitors. CONCLUSIONS: Levels of DHA-derived epoxides are lower in colon tissues from patients with UC than healthy and resolving mucosa. Production of these metabolites by gut endothelium requires MFSD2A; endothelial progenitor cells that overexpress MFSD2A reduce colitis in mice. This pathway might be induced to resolve intestinal inflammation in patients with colitis.


Assuntos
Colite/prevenção & controle , Colo/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Células Progenitoras Endoteliais/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Células Cultivadas , Colite/induzido quimicamente , Colite/genética , Colite/metabolismo , Colo/efeitos dos fármacos , Colo/patologia , Sistema Enzimático do Citocromo P-450/metabolismo , Sulfato de Dextrana , Modelos Animais de Doenças , Ácidos Docosa-Hexaenoicos/farmacologia , Células Progenitoras Endoteliais/efeitos dos fármacos , Células Progenitoras Endoteliais/patologia , Células Progenitoras Endoteliais/transplante , Compostos de Epóxi/metabolismo , Humanos , Proteínas de Membrana Transportadoras/genética , Camundongos Nus , Oxilipinas/metabolismo , Interferência de RNA , Transdução de Sinais , Simportadores , Transfecção , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Supressoras de Tumor/genética
12.
Nucleic Acids Res ; 44(4): 1579-90, 2016 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-26511095

RESUMO

Cancer stem cells (CSCs) have been identified in several solid malignancies and are now emerging as a plausible target for drug discovery. Beside the questionable existence of CSCs specific markers, the expression of CD133 was reported to be responsible for conferring CSC aggressiveness. Here, we identified two G-rich sequences localized within the introns 3 and 7 of the CD133 gene able to form G-quadruplex (G4) structures, bound and stabilized by small molecules. We further showed that treatment of patient-derived colon CSCs with G4-interacting agents triggers alternative splicing that dramatically impairs the expression of CD133. Interestingly, this is strongly associated with a loss of CSC properties, including self-renewing, motility, tumor initiation and metastases dissemination. Notably, the effects of G4 stabilization on some of these CSC properties are uncoupled from DNA damage response and are fully recapitulated by the selective interference of the CD133 expression.In conclusion, we provided the first proof of the existence of G4 structures within the CD133 gene that can be pharmacologically targeted to impair CSC aggressiveness. This discloses a class of potential antitumoral agents capable of targeting the CSC subpopulation within the tumoral bulk.


Assuntos
Antígenos CD/genética , Quadruplex G , Glicoproteínas/genética , Invasividade Neoplásica/genética , Células-Tronco Neoplásicas/metabolismo , Peptídeos/genética , Antígeno AC133 , Antígenos CD/química , Linhagem Celular Tumoral , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Glicoproteínas/química , Humanos , Células-Tronco Neoplásicas/patologia , Peptídeos/química , Biossíntese de Proteínas
13.
PLoS Genet ; 11(6): e1005167, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26110528

RESUMO

Telomeres are nucleoprotein complexes that protect the ends of linear chromosomes from incomplete replication, degradation and detection as DNA breaks. Mammalian telomeres are protected by shelterin, a multiprotein complex that binds the TTAGGG telomeric repeats and recruits a series of additional factors that are essential for telomere function. Although many shelterin-associated proteins have been so far identified, the inventory of shelterin-interacting factors required for telomere maintenance is still largely incomplete. Here, we characterize AKTIP/Ft1 (human AKTIP and mouse Ft1 are orthologous), a novel mammalian shelterin-bound factor identified on the basis of its homology with the Drosophila telomere protein Pendolino. AKTIP/Ft1 shares homology with the E2 variant ubiquitin-conjugating (UEV) enzymes and has been previously implicated in the control of apoptosis and in vesicle trafficking. RNAi-mediated depletion of AKTIP results in formation of telomere dysfunction foci (TIFs). Consistent with these results, AKTIP interacts with telomeric DNA and binds the shelterin components TRF1 and TRF2 both in vivo and in vitro. Analysis of AKTIP- depleted human primary fibroblasts showed that they are defective in PCNA recruiting and arrest in the S phase due to the activation of the intra S checkpoint. Accordingly, AKTIP physically interacts with PCNA and the RPA70 DNA replication factor. Ft1-depleted p53-/- MEFs did not arrest in the S phase but displayed significant increases in multiple telomeric signals (MTS) and sister telomere associations (STAs), two hallmarks of defective telomere replication. In addition, we found an epistatic relation for MST formation between Ft1 and TRF1, which has been previously shown to be required for replication fork progression through telomeric DNA. Ch-IP experiments further suggested that in AKTIP-depleted cells undergoing the S phase, TRF1 is less tightly bound to telomeric DNA than in controls. Thus, our results collectively suggest that AKTIP/Ft1 works in concert with TRF1 to facilitate telomeric DNA replication.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas/metabolismo , Telômero/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/genética , Ciclo Celular/genética , Células Cultivadas , Dano ao DNA/genética , Replicação do DNA , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Fibroblastos/fisiologia , Genes p53 , Humanos , Camundongos , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Proteínas/genética , Telômero/genética , Proteína 1 de Ligação a Repetições Teloméricas/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo
14.
Int J Mol Sci ; 19(2)2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29462928

RESUMO

New strategies are being investigated to ameliorate the efficacy and reduce the toxicity of the drugs currently used in colorectal cancer (CRC), one of the most common malignancies in the Western world. Data have been accumulated demonstrating that the antineoplastic therapies with either conventional or single-targeted drugs could take advantage from a combined treatment with omega-3 polyunsaturated fatty acids (omega-3 PUFA). These nutrients, shown to be safe at the dosage generally used in human trials, are able to modulate molecules involved in colon cancer cell growth and survival. They have also the potential to act against inflammation, which plays a critical role in CRC development, and to increase the anti-cancer immune response. In the present study, omega-3 PUFA were encapsulated in solid lipid nanoparticles (SLN) having a lipid matrix containing resveratrol esterified to stearic acid. Our aim was to increase the efficiency of the incorporation of these fatty acids into the cells and prevent their peroxidation and degradation. The Resveratrol-based SLN were characterized and investigated for their antioxidant activity. It was observed that the encapsulation of omega-3 PUFA into the SLN enhanced significantly their incorporation in human HT-29 CRC cells in vitro, and their growth inhibitory effects in these cancer cells, mainly by reducing cell proliferation.


Assuntos
Antineoplásicos/administração & dosagem , Antioxidantes/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Nanopartículas/química , Estilbenos/química , Animais , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Células HCT116 , Células HT29 , Humanos , Nanopartículas/metabolismo , Ratos , Resveratrol , Ácidos Esteáricos/química
15.
Mol Genet Metab ; 121(2): 180-189, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28456385

RESUMO

Pantothenate Kinase-Associated Neurodegeneration (PKAN) is a form of Neurodegeneration with Brain Iron Accumulation (NBIA) associated with mutations in the pantothenate kinase 2 gene (PANK2). The PANK2 catalyzes the first step of coenzyme A (CoA) biosynthesis, a pathway producing an essential cofactor that plays a key role in energy and lipid metabolism. The majority of PANK2 mutations reduces or abolishes the activity of the enzyme. In around 10% of cases with PKAN, the presence of deformed red blood cells with thorny protrusions in the circulation has been detected. Changes in membrane protein expression and assembly during erythropoiesis were previously explored in patients with PKAN. However, data on red blood cell membrane phospholipid organization are still missing in this disease. In this study, we performed lipidomic analysis on red blood cells from Italian patients affected by PKAN with a particular interest in membrane physico-chemical properties. We showed an increased number of small red blood cells together with membrane phospholipid alteration, particularly a significant increase in sphingomyelin (SM)/phosphatidylcholine (PC) and SM/phosphatidylethanolamine (PE) ratios, in subjects with PKAN. The membrane structural abnormalities were associated with membrane fluidity perturbation. These morphological and functional characteristics of red blood cells in patients with PKAN offer new possible tools in order to shed light on the pathogenesis of the disease and to possibly identify further biomarkers for clinical studies.


Assuntos
Membrana Eritrocítica/química , Lipídeos de Membrana/sangue , Neurodegeneração Associada a Pantotenato-Quinase/sangue , Neurodegeneração Associada a Pantotenato-Quinase/fisiopatologia , Fosfolipídeos/sangue , Adulto , Biomarcadores/sangue , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Membrana Eritrocítica/fisiologia , Feminino , Humanos , Ferro/metabolismo , Imageamento por Ressonância Magnética , Masculino , Fluidez de Membrana , Lipídeos de Membrana/química , Proteínas de Membrana/genética , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Mutação , Neurodegeneração Associada a Pantotenato-Quinase/genética , Fosfolipídeos/química , Adulto Jovem
16.
Nucleic Acids Res ; 43(3): 1759-69, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25618850

RESUMO

Here, with the aim of obtaining insight into the intriguing selectivity of G-quadruplex (G4) ligands toward cancer compared to normal cells, a genetically controlled system of progressive transformation in human BJ fibroblasts was analyzed. Among the different comparative evaluations, we found a progressive increase of DNA damage response (DDR) markers throughout the genome from normal toward immortalized and transformed cells. More interestingly, sensitivity to G4 ligands strongly correlated with the presence of a basal level of DNA damage, including at the telomeres, where the chromosome ends were exposed to the DDR without concurrent induction of DNA repair activity, as revealed by the lack of 53BP1 recruitment and telomere aberrations. The link between telomere uncapping and the response to G4 stabilization was directly assessed by showing that a partial TRF2 depletion, causing a basal level of telomere localized DDR, rendered telomerized fibroblasts prone to G4-induced telomere damage and anti-proliferative defects. Taken together these data strongly indicate that the presence of a basal level of telomere-associated DDR is a determinant of susceptibility to G4 stabilization.


Assuntos
Dano ao DNA , Quadruplex G/efeitos dos fármacos , Neoplasias/genética , Telômero , Western Blotting , Imunoprecipitação da Cromatina , Humanos , Hibridização in Situ Fluorescente , Células Tumorais Cultivadas
17.
Int J Mol Sci ; 18(12)2017 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-29261109

RESUMO

Chemotherapy efficacy is strictly limited by the resistance of cancer cells. The ω-3 long chain polyunsaturated fatty acids (ω-3 LCPUFAs) are considered chemosensitizing agents and revertants of multidrug resistance by pleiotropic, but not still well elucidated, mechanisms. Nowadays, it is accepted that alteration in gene expression, modulation of cellular proliferation and differentiation, induction of apoptosis, generation of reactive oxygen species, and lipid peroxidation are involved in ω-3 LCPUFA chemosensitizing effects. A crucial mechanism in the control of cell drug uptake and efflux is related to ω-3 LCPUFA influence on membrane lipid composition. The incorporation of docosahexaenoic acid in the lipid rafts produces significant changes in their physical-chemical properties affecting content and functions of transmembrane proteins, such as growth factors, receptors and ATP-binding cassette transporters. Of note, ω-3 LCPUFAs often alter the lipid compositions more in chemoresistant cells than in chemosensitive cells, suggesting a potential adjuvant role in the treatment of drug resistant cancers.


Assuntos
Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ácidos Graxos Ômega-3/farmacologia , Animais , Humanos , Microdomínios da Membrana/efeitos dos fármacos
18.
Nucleic Acids Res ; 42(5): 2945-57, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24335081

RESUMO

Tumor angiogenesis is mainly mediated by vascular endothelial growth factor (VEGF), a pro-angiogenic factor produced by cancer cells and active on the endothelium through the VEGF receptor 2 (VEGFR-2). Here we identify a G-rich sequence within the proximal promoter region of vegfr-2, able to form an antiparallel G-quadruplex (G4) structure. This G4 structure can be efficiently stabilized by small molecules with the consequent inhibition of vegfr-2 expression. Functionally, the G4-mediated reduction of VEGFR-2 protein causes a switching off of signaling components that, converging on actin cytoskeleton, regulate the cellular events leading to endothelial cell proliferation, migration and differentiation. As a result of endothelial cell function impairment, angiogenic process is strongly inhibited by G4 ligands both in vitro and in vivo. Interestingly, the G4-mediated antiangiogenic effect seems to recapitulate that observed by using a specific interference RNA against vegfr-2, and it is strongly antagonized by overexpressing the vegfr-2 gene. In conclusion, we describe the evidence for the existence of G4 in the promoter of vegfr-2, whose expression and function can be markedly inhibited by G4 ligands, thereby revealing a new, and so far undescribed, way to block VEGFR-2 as target for anticancer therapy.


Assuntos
Quadruplex G , Neoplasias/irrigação sanguínea , Neovascularização Patológica , Regiões Promotoras Genéticas , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Animais , Linhagem Celular Tumoral , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Neovascularização Fisiológica , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
19.
Biochim Biophys Acta ; 1840(10): 3115-22, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25018005

RESUMO

BACKGROUND: Detergent resistant membranes (DRMs) are a useful model system for the in vitro characterization of cell membrane domains. Indeed, DRMs provide a simple model to study the mechanisms underlying several key cell processes based on the interplay between specific cell membrane domains on one hand, and specific proteins and/or lipids on the other. Considering therefore their biological relevance, the development of methods capable to provide information on the composition and structure of membrane domains and to detect their modifications is highly desirable. In particular, Fourier transform infrared (FTIR) spectroscopy is a vibrational tool widely used for the study not only of isolated and purified biomolecules but also of complex biological systems, including intact cells and tissues. One of the main advantages of this non-invasive approach is that it allows obtaining a molecular fingerprint of the sample under investigation in a rapid and label-free way. METHODS: Here we present an FTIR characterization of DRM fractions purified from the human breast cancer cells MCF-7, before and after treatment with the omega 3 fatty acid docosahexaenoic acid (DHA), which was found to promote membrane microdomain reorganization. RESULTS AND CONCLUSIONS: We will show that FTIR spectroscopy coupled with multivariate analysis enables to monitor changes in the composition of DRMs, induced in particular by the incorporation of DHA in cell membrane phospholipids. GENERAL SIGNIFICANCE: This study paves the way for a new label-free characterization of specific membrane domains within intact cells, which could provide complementary information to the fluorescence approaches presently used.


Assuntos
Ácidos Docosa-Hexaenoicos/química , Microdomínios da Membrana/química , Modelos Químicos , Fosfolipídeos/química , Linhagem Celular Tumoral , Ácidos Docosa-Hexaenoicos/metabolismo , Análise de Fourier , Humanos , Microdomínios da Membrana/metabolismo , Fosfolipídeos/metabolismo
20.
Lipids Health Dis ; 14: 139, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26511930

RESUMO

BACKGROUND: Nowadays no researches has been performed on fatty acid profile (FA) and desaturase activity in metabolically healthy obesity (MHO). The aim of this study was to assessed gender and BMI-related difference in FA, estimated desaturase activities and the efficacy on metabolic changes produced by 2-months well-balance diet in MHO subjects. METHODS: In 103 MHO subjects (30/73 M/F; age:42.2 ± 9.5) FA, estimated desaturase activity, body composition (by DXA), Body Mass Index (BMI), lipid profile, adipokines (leptin, adiponectin, grelin, glucagon-like peptide-1), insulin resistence (by Homestasis metabolic assessment), C-reactive proteine, Atherogenic index of plasma (AIP) and Body Shape Index (ABSI) have been assessed. Gender and BMI related difference have been evaluated and the efficacy produced by 2-months well-balance diet has been considered. RESULTS: At baseline, obese subjects, compared to overweight, show a significantly higher oleic (p <0.050), monounsaturated fatty acids (p <0.040), C18:0 delta-9 desaturase activity (D9D) (p <0.040) and lower linoleic acid (p <0.020), polyunsaturated fatty acids (p <0.020) and n-6 LCPUFA (p <0.010). Concerning gender-related difference, women show a significantly higher arachidonic acid (p <0.001), polyunsaturated fatty acids (p <0.001), n-6 LCPUFA (p <0.002), and lower monounsaturated fatty acids (p <0.001), D6D activity (p <0.030), C18:0 D9D (0.000) and C16:0 D9D (p <0.030). The 2-months diet was associated with a significantly increase in arachidonic acid (p = 0.007), eicosapentaenoic acid (p = 0.030), docosahexaenoic acid (p <0.001), long chain omega 3 polyunsaturated fatty acids (n-3 LCPUFA) (p <0.001), delta-5 desaturase activity (D5D) (p = 0.002), glucagon like peptide-1 (p <0.001) and a significant decrease in palmitoleic acid (p = <0.030), n-6/n-3 LCPUFA (p <0.001), insulin resistance (p = 0.006), leptin (p = 0.006), adiponectin (p <0.001), grelin (p = 0.030), CRP (p = 0.004), BMI (p <0.001) and android fat mass (p <0.001). CONCLUSIONS: The balanced diet intervention was effective in improving metabolic indices.


Assuntos
Índice de Massa Corporal , Dieta , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Obesidade Metabolicamente Benigna/sangue , Adiponectina/sangue , Adulto , Ácido Araquidônico/sangue , Composição Corporal , Proteína C-Reativa/metabolismo , Dessaturase de Ácido Graxo Delta-5 , Ácidos Graxos Dessaturases/sangue , Ácidos Graxos Monoinsaturados/sangue , Ácidos Graxos Insaturados/sangue , Feminino , Grelina/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Resistência à Insulina , Leptina/sangue , Ácido Linoleico/sangue , Masculino , Pessoa de Meia-Idade , Obesidade Metabolicamente Benigna/tratamento farmacológico , Fatores Sexuais , Triglicerídeos/sangue
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