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1.
Int J Mol Sci ; 23(8)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35457065

RESUMO

The drugs used for cancer treatment have many drawbacks, as they damage both tumor and healthy cells and, in addition, they tend to be poorly soluble drugs. Their transport in nanoparticles can solve these problems as these can release the drug into tumor tissues, as well as improve their solubility, bioavailability, and efficacy, reducing their adverse effects. This article focuses on the advantages that nanotechnology can bring to medicine, with special emphasis on nanoliposomes. For this, a review has been made of the nanoliposomal systems marketed for the treatment of cancer, as well as those that are in the research phase, highlighting the clinical trials being carried out. All marketed liposomes studied are intravenously administered, showing a reduced intensity of side-effects compared with the nonliposomal form. Doxorubicin is the active ingredient most frequently employed. Ongoing clinical trials expand the availability of liposomal medicines with new clinical indications. In conclusion, the introduction of drugs in nanoliposomes means an improvement in their efficacy and the quality of life of patients. The future focus of research could be directed to develop multifunctional targeted nanoliposomes using new anticancer drugs, different types of existing drugs, or new standardized methodologies easily translated into industrial scale.


Assuntos
Nanopartículas , Neoplasias , Doxorrubicina/uso terapêutico , Humanos , Lipossomos , Neoplasias/tratamento farmacológico , Qualidade de Vida
2.
Redox Biol ; 28: 101324, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539805

RESUMO

Acute pancreatitis is an inflammatory process of the pancreatic gland that may lead to dysregulation of the trans-sulfuration pathway. The aims of this work were firstly to study the methionine cycle as well as the trans-sulfuration pathway using metabolomic and proteomic approaches identifying the causes of this dysregulation in an experimental model of acute pancreatitis; and secondly to reveal the effects of S-adenosylmethionine administration on these pathways. Acute pancreatitis was induced by cerulein in mice, and a group of animals received S-adenosylmethionine treatment. Cerulein-induced acute pancreatitis rapidly caused marked depletion of methionine, S-adenosylmethionine, 5'-methylthioadenosine, cystathionine, cysteine, and glutathione levels in pancreas, but S-adenosylhomocysteine and homocysteine remained unchanged. Protein steady-state levels of S-adenosylhomocysteine-hydrolase and cystathionine gamma-lyase diminished but methylthioadenosine phosphorylase levels increased in pancreas with acute pancreatitis. Although cystathionine ß-synthase protein levels did not change with acute pancreatitis, Nos2 mRNA and protein levels were markedly up-regulated and caused tyrosine nitration of cystathionine ß-synthase in pancreas. S-adenosylmethionine administration enhanced Nos2 mRNA expression and cystathionine ß-synthase nitration and triggered homocysteine accumulation in acute pancreatitis. Furthermore, S-adenosylmethionine administration promoted enrichment of the euchromatin marker H3K4me3 in the promoters of Tnf-α, Il-6, and Nos2 and enhanced the mRNA up-regulation of these genes. Accordingly, S-adenosylmethionine administration increased inflammatory infiltrate and edema in pancreas with acute pancreatitis. In conclusion, tyrosine-nitration of cystathionine ß-synthase blockades the trans-sulfuration pathway in acute pancreatitis promoting homocysteine accumulation upon S-adenosylmethionine treatment.


Assuntos
Ceruletídeo/efeitos adversos , Cistationina beta-Sintase/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Pancreatite/metabolismo , Animais , Cistationina/metabolismo , Cisteína/metabolismo , Modelos Animais de Doenças , Glutationa/metabolismo , Homocisteína/metabolismo , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Pancreatite/induzido quimicamente , Pancreatite/etiologia , S-Adenosilmetionina/administração & dosagem , Regulação para Cima
3.
Redox Biol ; 16: 276-284, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29567616

RESUMO

p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-out mice. Liver-specific p38α deficiency triggered a dramatic down-regulation of the mRNAs of the key antioxidant enzymes glutamate cysteine ligase, superoxide dismutase 1, superoxide dismutase 2, and catalase in young mice, which seems mediated by the lack of p65 recruitment to their promoters. Nrf-2 nuclear levels did not change significantly in the liver of young mice upon p38α deficiency, but nuclear levels of phospho-p65 and PGC-1α decreased in these mice. p38α-dependent activation of NF-κB seems to occur through classical IκB Kinase and via ribosomal S6 kinase1 and AKT in young mice. However, unexpectedly the long-term deficiency in p38α triggers a compensatory up-regulation of antioxidant enzymes via NF-κB activation and recruitment of p65 to their promoters. In conclusion, p38α MAPK maintains the expression of antioxidant genes in liver of young animals via NF-κΒ under basal conditions, whereas its long-term deficiency triggers compensatory up-regulation of antioxidant enzymes through NF-κΒ.


Assuntos
Envelhecimento/genética , Antioxidantes/metabolismo , Fígado/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Animais , Catalase/genética , Estresse do Retículo Endoplasmático/genética , Regulação Enzimológica da Expressão Gênica , Glutamato-Cisteína Ligase/genética , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/genética , Superóxido Dismutase/genética , Superóxido Dismutase-1/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Eur J Pharm Biopharm ; 119: 361-371, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28709903

RESUMO

The therapy of inflammatory bowel diseases is still rather inefficient, and about 80% of patients require surgery at some stage. Improving the treatments by more efficient medication is, therefore, an urgent medical need. The objective of this project was to demonstrate targeted delivery of Cyclosporine-A (CYA) to the inflamed areas of the intestinal mucosa after oral administration, enabling improved alleviation of the symptoms and, at the same time, reduced systemic drug absorption and associated adverse effects. As had already been demonstrated in previous studies, nano- to micrometer-sized drug particles will accumulate at inflamed mucosal areas, providing a platform for such purposes. CYA as incorporated in poly-(lactic-co-glycolic-Acid) (PLGA) nano- and mirocarriers, respectively, each homogeneous in size and providing controlled drug release over 24h at intestinal pH-value. For comparative reasons, a commercial formulation (Sandimmun Neoral®) was included in the study. In an acute model of DSS-induced inflammation in Balb/c mice, up to three doses were administered for each formulation: 50mg/kg, 25mg/kg and 12.5mg/kg. Drug-free particles were included as control. The following parameters were evaluated: body weight, colon length, colon weight/length ratio, cytokine expression and histological analysis. Plasma levels of CYA were analysed to compare systemic bioavailability. While disease parameters, such as, e.g. colon length, always improved with an optimum dose of 25mg/kg, the commercial and the microparticulate formulations led to measurable plasma levels and adverse effects in terms of body weight loss at the highest dose. In contrast, when administering the same doses as nanoparticles, plasma concentrations remained always below the detection limit, and the body weight of the animals remained unchanged. In conclusion, this study corroborates the potential of nanocarriers enabling an improved topical delivery of CYA to the inflamed gut mucosa after oral administration yielding the same improvement of disease parameters at only half the dose in comparison to microparticles and a commercial oral formulation, respectively, and at the same time minimizing systemic exposure and associated adverse effect.


Assuntos
Ciclosporina/química , Ciclosporina/farmacologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Nanopartículas/química , Polímeros/química , Administração Oral , Animais , Disponibilidade Biológica , Colo/metabolismo , Modelos Animais de Doenças , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Mucosa Intestinal/metabolismo , Ácido Láctico/química , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
5.
PLoS One ; 12(2): e0171738, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28166285

RESUMO

BACKGROUND: Hepatocyte poliploidization is an age-dependent process, being cytokinesis failure the main mechanism of polyploid hepatocyte formation. Our aim was to study the role of p38α MAPK in the regulation of actin cytoskeleton and cytokinesis in hepatocytes during development and aging. METHODS: Wild type and p38α liver-specific knock out mice at different ages (after weaning, adults and old) were used. RESULTS: We show that p38α MAPK deficiency induces actin disassembly upon aging and also cytokinesis failure leading to enhanced binucleation. Although the steady state levels of cyclin D1 in wild type and p38α knock out old livers remained unaffected, cyclin B1- a marker for G2/M transition- was significantly overexpressed in p38α knock out mice. Our findings suggest that hepatocytes do enter into S phase but they do not complete cell division upon p38α deficiency leading to cytokinesis failure and binucleation. Moreover, old liver-specific p38α MAPK knock out mice exhibited reduced F-actin polymerization and a dramatic loss of actin cytoskeleton. This was associated with abnormal hyperactivation of RhoA and Cdc42 GTPases. Long-term p38α deficiency drives to inactivation of HSP27, which seems to account for the impairment in actin cytoskeleton as Hsp27-silencing decreased the number and length of actin filaments in isolated hepatocytes. CONCLUSIONS: p38α MAPK is essential for actin dynamics with age in hepatocytes.


Assuntos
Actinas/metabolismo , Citocinese , Citoesqueleto/metabolismo , Hepatócitos/fisiologia , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Actinas/química , Animais , Biomarcadores , Células Cultivadas , Senescência Celular , Citocinese/genética , Técnicas de Inativação de Genes , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase 14 Ativada por Mitógeno/genética , Mitose/genética , Ligação Proteica , Multimerização Proteica , Proteínas Serina-Treonina Quinases/metabolismo
6.
Free Radic Biol Med ; 104: 75-103, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28062361

RESUMO

Redox signaling regulates physiological self-renewal, proliferation, migration and differentiation in gastrointestinal epithelium by modulating Wnt/ß-catenin and Notch signaling pathways mainly through NADPH oxidases (NOXs). In the intestine, intracellular and extracellular thiol redox status modulates the proliferative potential of epithelial cells. Furthermore, commensal bacteria contribute to intestine epithelial homeostasis through NOX1- and dual oxidase 2-derived reactive oxygen species (ROS). The loss of redox homeostasis is involved in the pathogenesis and development of a wide diversity of gastrointestinal disorders, such as Barrett's esophagus, esophageal adenocarcinoma, peptic ulcer, gastric cancer, ischemic intestinal injury, celiac disease, inflammatory bowel disease and colorectal cancer. The overproduction of superoxide anion together with inactivation of superoxide dismutase are involved in the pathogenesis of Barrett's esophagus and its transformation to adenocarcinoma. In Helicobacter pylori-induced peptic ulcer, oxidative stress derived from the leukocyte infiltrate and NOX1 aggravates mucosal damage, especially in HspB+ strains that downregulate Nrf2. In celiac disease, oxidative stress mediates most of the cytotoxic effects induced by gluten peptides and increases transglutaminase levels, whereas nitrosative stress contributes to the impairment of tight junctions. Progression of inflammatory bowel disease relies on the balance between pro-inflammatory redox-sensitive pathways, such as NLRP3 inflammasome and NF-κB, and the adaptive up-regulation of Mn superoxide dismutase and glutathione peroxidase 2. In colorectal cancer, redox signaling exhibits two Janus faces: On the one hand, NOX1 up-regulation and derived hydrogen peroxide enhance Wnt/ß-catenin and Notch proliferating pathways; on the other hand, ROS may disrupt tumor progression through different pro-apoptotic mechanisms. In conclusion, redox signaling plays a critical role in the physiology and pathophysiology of gastrointestinal tract.


Assuntos
Gastroenteropatias/metabolismo , Trato Gastrointestinal/metabolismo , NADPH Oxidases/metabolismo , Estresse Oxidativo , Proliferação de Células/genética , Gastroenteropatias/patologia , Trato Gastrointestinal/patologia , Humanos , Mucosa Intestinal/metabolismo , Intestinos/patologia , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Compostos de Sulfidrila/metabolismo , Via de Sinalização Wnt/genética
7.
Crit Rev Clin Lab Sci ; 52(4): 159-67, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26104038

RESUMO

Dysregulation of the cell cycle leads to polyploid cells, which are classified into mononuclear or binuclear polyploid cells depending on the number of nuclei. Polyploidy is common in plants and in animals. Physiologically, polyploidy and binucleation are differentiation markers and also features of the aging process. In fact, although they provide multiple copies of genes required for survival, a negative correlation between growth capacity and polyploidy has been reported, and thus, suppression or reversal of this phenomenon may be a growth advantage. On the other hand, unscheduled polyploidization may cause genomic instability that might lead to neoplastic aneuploidy. The aim of this review is to analyze the mechanisms that lead to polyploidy, and particularly binucleation, and highlight the potential of ploidy as a marker of illness severity or the success of the adaptive response for an injury, with special emphasis in the liver under physiological and pathological conditions. Hepatocyte binucleation occurs in late fetal development and postnatal maturation, especially after weaning via phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt). It also increases upon aging of the liver as well as in liver cirrhosis and cancer. Liver binucleation mainly indicates the severity of the damage. Furthermore, the eventual increase in hepatocyte binucleation points out compensatory proliferation associated with liver injury. Ploidy conveyor would also permit hepatocyte adaptation to xenobiotic or nutritional injury. In contrast, polyploidy is a feature of many human cancers, and it may predispose to genomic instability and generation of aneuploidization that play a major role in carcinogenesis. Finally, a better understanding of the polyploidization process is needed in order to approach clinical research but also, to get deeper knowledge of cell cycle control. The fascinating regulation of cell cycle in liver and the generation and reversal of ploidies will provide more clues for the mystery of liver regeneration.


Assuntos
Citocinese , Animais , Ciclo Celular , Células Cultivadas , Hepatócitos , Humanos , Neoplasias Hepáticas , Regeneração Hepática , Camundongos , Camundongos Knockout
8.
Food Chem Toxicol ; 80: 80-84, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25765751

RESUMO

One of the major sources of flavonoids for humans are citrus fruits, hesperidin being the predominant flavonoid. Hesperetin (HSP), the aglycon of hesperidin, has been reported to provide health benefits such as antioxidant, anti-inflammatory and anticarcinogenic effects. However, the effect of HSP on skin pigmentation is not clear. Some authors have found that HSP induces melanogenesis in murine B16-F10 melanoma cells, which, if extrapolated to in vivo conditions, might protect skin against photodamage. Since the effect of HSP on normal melanocytes could be different to that observed on melanoma cells, the described effect of HSP on murine melanoma cells has been compared to the effect obtained using normal human melanocytes. HSP concentrations of 25 and 50 µM induced melanin synthesis and tyrosinase activity in human melanocytes in a concentration-dependent manner. Compared to control melanocytes, 25 µM HSP increased melanin production and tyrosinase activity 1.4-fold (p < 0.01) and 1.1-fold (p < 0.01), respectively, and the corresponding increases in the case of 50 µM HSP were 1.9-fold (p < 0.001) and 1.3-fold (p < 0.001). Therefore, HSP could be considered a valuable photoprotective substance if its capacity to increase melanin production in human melanocyte cultures could be reproduced on human skin.


Assuntos
Células Epidérmicas , Hesperidina/farmacologia , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Animais , Linhagem Celular , Hesperidina/administração & dosagem , Humanos , Melanoma , Camundongos , Estrutura Molecular
9.
Free Radic Biol Med ; 75 Suppl 1: S19, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26461300

RESUMO

Cytokinesis is the last step in mitosis and it implies re-organization of the actin cytoskeleton. Its failure is one of the major mechanisms of polyploidy and binucleation in mammals. Our aims were 1) to assess the role of redox-sensitive p38α MAPK in cytokinesis by studying the liver of wild type mice or liver-specific p38α knock-out mice; 2) to assess the role of oxidative stress associated with hepatocyte isolation on cytokinesis. When p38α was down-regulated in hepatocytes, MK2 phosphorylation on threonine 334 was completely abrogated. Activation of MNK-1, required for abscission of the intercellular bridge, was diminished. Key proteins of the RhoA pathway (phospho-PRK2, nuclear phosphorylated cofilin, and cytosolic p27) were assessed confirming the impairment of this pathway. The absence of p38α in aging liver also led to a decrease in HSP27 phosphorylation, which is required for actin polymerization. Indeed, a severe impairment in the F-actin filamentous structure was found in the liver of old mice upon p38α deficiency. Consequently, long-term p38α MAPK down-regulation markedly affects the RhoA pathway and actin cytoskeleton dynamics inducing actin disassembly and cytokinesis failure upon aging. On the other hand, hepatocyte isolation caused marked glutathione depletion, increased generation of reactive oxygen species, and activated cell cycle entry. Addition of N-acetyl cysteine to isolation media prevented glutathione depletion, restrained the cell cycle entry, and abrogated defective cytokinesis and the formation of binucleated hepatocytes during isolation. Our results show that hepatocytes do enter into S phase but they do not complete cell division with age upon p38α deficiency or upon oxidative stress associated with isolation leading in both cases to cytokinesis failure and binucleation.

10.
Free Radic Biol Med ; 75 Suppl 1: S52, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26461407

RESUMO

p38a MAPK may function as a mediator of reactive oxygen species signaling and thus p38a is considered a sensor of oxidative stress. In liver-specific p38a knock-out (KO) adult mice we previously found glutathione depletion and down-regulation of antioxidant enzymes. Our aim was to assess the influence of long-term p38a deficiency on oxidative stress and on the regulation of antioxidant enzymes in liver of old mice. To this end, wild type or liver-specific KO mice after weaning, at 4-6 months of age, or at 24 months of age were used. Reduced glutathione (GSH) and oxidized glutathione levels were determined by mass spectrometry, gene expression of antioxidant enzymes was determined by RT-PCR, and induction of NRF-2 and PGC-1a as well as activation of NF-?B were assessed by western blotting. We report that GSH levels decreased upon aging only in liver of wild-type mice, but not in p38a KO mice. The mRNA expression of glutathione peroxidase, Cu-Zn superoxide dismutase, Mn-superoxide dismutase, and glutamate cysteine ligase was up-regulated in adult wild-type in comparison with mice after weaning, but their gene expression was down-regulated in old wild-type mice. Although the mRNA expression of glutathione peroxidase, Cu-Zn superoxide dismutase, Mn-superoxide dismutase, and glutamate cysteine ligase was down-regulated in adult KO mice vs KO mice after weaning, their gene expression was up-regulated in old KO mice. This up-regulation was not associated with nuclear translocation of NRF-2, which decreased upon aging in KO mice, nor with up-regulation of PGC-1a. However, phosphorylation of p65 was markedly increased in old KO mice as an index of NF-?B activation. In conclusion, long term deficiency of p38a in the liver causes compensatory activation of NF?B that is likely to be responsible for the up-regulation of antioxidant enzymes upon aging, independently of Nrf-2 and PGC-1a.

11.
Hepatology ; 57(5): 1950-61, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23354775

RESUMO

UNLABELLED: p38α mitogen-activated protein kinases (MAPK) may be essential in the up-regulation of proinflammatory cytokines and can be activated by transforming growth factor ß, tumor necrosis factor-α, interleukin-1ß, and oxidative stress. p38 MAPK activation results in hepatocyte growth arrest, whereas increased proliferation has been considered a hallmark of p38α-deficient cells. Our aim was to assess the role of p38α in the progression of biliary cirrhosis induced by chronic cholestasis as an experimental model of chronic inflammation associated with hepatocyte proliferation, apoptosis, oxidative stress, and fibrogenesis. Cholestasis was induced in wildtype and liver-specific p38α knockout mice by bile duct ligation and animals were sacrificed at 12 and 28 days. p38α knockout mice exhibited a 50% decrease in mean life-span after cholestasis induction. MK2 phosphorylation was markedly reduced in liver of p38α-deficient mice upon chronic cholestasis. Hepatocyte growth was reduced and hepatomegaly was absent in p38α-deficient mice during chronic cholestasis through down-regulation of both AKT and mammalian target of rapamycin. Cyclin D1 and cyclin B1 were up-regulated in liver of p38α-deficient mice upon chronic cholestasis, but unexpectedly proliferating cell nuclear antigen was down-regulated at 12 days after cholestasis induction and the mitotic index was very high upon cholestasis in p38α-deficient mice. p38α-knockout hepatocytes exhibited cytokinesis failure evidenced by an enhanced binucleation rate. As chronic cholestasis evolved the binucleation rate decreased in wildtype animals, whereas it remained high in p38α-deficient mice. CONCLUSION: Our results highlight a key role of p38α in hepatocyte proliferation, in the development of hepatomegaly, and in survival during chronic inflammation such as biliary cirrhosis.


Assuntos
Proliferação de Células , Citocinese , Cirrose Hepática Biliar/metabolismo , Cirrose Hepática Biliar/patologia , Fígado/metabolismo , Fígado/patologia , Proteína Quinase 14 Ativada por Mitógeno/deficiência , Animais , Apoptose/fisiologia , Doença Crônica , Ciclina B1/metabolismo , Ciclina D1/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Hepatócitos/metabolismo , Hepatócitos/patologia , Cirrose Hepática Biliar/mortalidade , MAP Quinase Quinase 2/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 14 Ativada por Mitógeno/genética , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Estresse Oxidativo/fisiologia , Transdução de Sinais/fisiologia , Taxa de Sobrevida
12.
J Neurochem ; 112(4): 1074-87, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19968760

RESUMO

Neurite formation involves coordinated changes between the actin cytoskeleton and the microtubule network. Rho GTPases are clearly implicated in several aspects of neuronal development and function. Indeed, RhoA is a negative regulator of neurite outgrowth and its effector Rho-kinase mediates the Rho-driven neurite retraction. Considering that RhoE/round protein (Rnd3) acts antagonistically to RhoA and it is also able to bind and inhibit rho kinase-I (p160ROCK) - ROCK-I, it is tempting to speculate a role of RhoE in neurite formation. We show for the first time that, in the absence of nerve growth factor (NGF), RhoE induces neurite-like outgrowth. Our results demonstrate that over-expression of RhoE decreases the activity of RhoA and reduces the expression of both ROCK-I and the phosphorylated myosin light chain phosphatase (MLCPp). Conversely, over-expression of either active RhoA or ROCK-I abolishes the RhoE-promoted neurite outgrowth, suggesting that RhoE induces neurite-like formation through inhibition of the RhoA/ROCK-I signalling. We also show that Rac and Cdc42 have a role in RhoE-induced neurite outgrowth. Finally, the present data further indicate that RhoE may be involved in the NGF-induced neurite outgrowth in PC12 cells, as depletion of RhoE by siRNA reduces the neurite formation induced by NGF. These findings provide new insights into the molecular mechanism implicated in neuronal development and may provide novel therapeutic targets in neurodegenerative disorders.


Assuntos
Neuritos/fisiologia , Transdução de Sinais/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Animais , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Fluorescência Verde/genética , Fator de Crescimento Neural/farmacologia , Neuritos/efeitos dos fármacos , Proteínas de Neurofilamentos/metabolismo , Células PC12/citologia , Células PC12/efeitos dos fármacos , RNA Interferente Pequeno/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transfecção/métodos , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/genética , Quinases Associadas a rho/antagonistas & inibidores
13.
Rev Esp Cardiol ; 59(9): 911-8, 2006 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-17020704

RESUMO

INTRODUCTION AND OBJECTIVES: Immune response-mediated regulation of myocardial collagen remains poorly understood. Our objective was to investigate the relationship between ventricular remodeling and immunologic activation in patients with heart failure (HF) by comparing dilated and ischemic cardiomyopathy. METHODS: We studied 94 patients with HF and dilated cardiomyopathy (n=46) or ischemic cardiomyopathy (n=48). We recorded left ventricular (LV) volumes, E/A ratio, and ejection fraction. Plasma concentrations of tumor necrosis factor alpha (TNFalpha), soluble TNFa receptor I (sTNF-RI), sTNF-RII, interleukin-6 (IL-6) and IL-10 were measured. The serum procollagen type-III amino-terminal propeptide (PIIINP) level was also obtained. RESULTS: Ventricular volumes were greater in the dilated cardiomyopathy than in the ischemic cardiomyopathy group (P< .05). However, sTNF-RI, sTNF-RII and PIIINP levels were higher in the ischemic group (P< .05). In this group, there were significant correlations between ventricular volumes and IL-10 and sTNF-RII levels. There was also a significant correlation between PIIINP and sTNF-RII levels (r=0.30; P< .05). In the dilated cardiomyopathy group, there was a significant correlation between ventricular volumes and IL-10 level, and between PIIINP level and IL-6 (r=0.32; P< .05) and sTNF-RII levels (r=0.32; P< .05). Multiple linear regression analysis, which included cytokine levels, age, sex and ventricular function, showed that the sTNF-RII level was an independent predictor of the PIIINP level (adjusted r(2)=0.16; P< .0001) and of ventricular volumes (LV end-systolic volume index, adjusted r(2)=0.034; P< .05; and LV end-diastolic volume index, adjusted r(2)=.048; P< .05) in both groups. CONCLUSIONS: In HF, there is an interaction between proinflammatory cytokines and the extracellular matrix. Immunologic implications vary according to disease etiology. The elevation in proinflammatory cytokine and PIIINP levels is greater in patients with ischemic cardiomyopathy. Multiple regression analysis showed that the sTNF-RII level was an independent predictor of ventricular remodeling.


Assuntos
Citocinas/sangue , Insuficiência Cardíaca/imunologia , Miocárdio/imunologia , Remodelação Ventricular , Idoso , Biomarcadores/sangue , Cardiotônicos/uso terapêutico , Citocinas/biossíntese , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Análise de Regressão
14.
World J Gastroenterol ; 12(36): 5834-45, 2006 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-17007050

RESUMO

AIM: To investigate and compare the hepatogenic transdifferentiation of adipose tissue-derived stem cells (ADSC) and bone marrow-derived mesenchymal stem cells (BMSC) in vitro. Transdifferentiation of BMSC into hepatic cells in vivo has been described. Adipose tissue represents an accessible source of ADSC, with similar characteristics to BMSC. METHODS: BMSCs were obtained from patients undergoing total hip arthroplasty and ADSC from human adipose tissue obtained from lipectomy. Cells were grown in medium containing 15% human serum. Cultures were serum deprived for 2 d before cultivating under similar pro-hepatogenic conditions to those of liver development using a 2-step protocol with sequential addition of growth factors, cytokines and hormones. Hepatic differentiation was RT-PCR-assessed and liver-marker genes were immunohistochemically analysed. RESULTS: BMSC and ADSC exhibited a fibroblastic morphology that changed to a polygonal shape when cells differentiated. Expression of stem cell marker Thy1 decreased in differentiated ADSC and BMSC. However, the expression of the hepatic markers, albumin and CYPs increased to a similar extent in differentiated BMSC and ADSC. Hepatic gene activation could be attributed to increased liver-enriched transcription factors (C/EBPbeta and HNF4alpha), as demonstrated by adenoviral expression vectors. CONCLUSION: Mesenchymal stem cells can be induced to hepatogenic transdifferentiation in vitro. ADSCs have a similar hepatogenic differentiation potential to BMSC, but a longer culture period and higher proliferation capacity. Therefore, adipose tissue may be an ideal source of large amounts of autologous stem cells, and may become an alternative for hepatocyte regeneration, liver cell transplantation or preclinical drug testing.


Assuntos
Tecido Adiposo/citologia , Células da Medula Óssea/citologia , Diferenciação Celular/fisiologia , Hepatócitos/citologia , Células-Tronco Mesenquimais/citologia , Tecido Adiposo/metabolismo , Tecido Adiposo/fisiologia , Adulto , Idoso , Albuminas/genética , Albuminas/metabolismo , Células da Medula Óssea/metabolismo , Células da Medula Óssea/fisiologia , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica/fisiologia , Fator 4 Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Hepatócitos/metabolismo , Humanos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , Pessoa de Meia-Idade , Fenótipo , Antígenos Thy-1/genética , Antígenos Thy-1/metabolismo , Ativação Transcricional
15.
Gastroenterol Hepatol ; 29(6): 366-76, 2006.
Artigo em Espanhol | MEDLINE | ID: mdl-16790188

RESUMO

There is an urgent need to search for alternatives to whole organ transplantation. Several methods have been proposed. Among these strategies, cell transplantation is currently one of the most promising. To achieve this aim, in addition to highly differentiated adult hepatocytes, the use of stem cells is considered a highly attractive therapeutic method for the treatment of liver disease and for temporary support of hepatic function until a liver becomes available for organ transplantation. This strategy is based on the ability of stem cells to differentiate into different cellular types according to their environment. Therefore, stem cells could be an unlimited source of hepatic cells for transplantation and gene therapy. Bone marrow is considered the most promising source of adult stem cells, partly due to the versatility of the cells obtained in repairing damaged tissues of several lineages. Several different types of stem cells have been described in bone marrow: hematopoietic, mesenchymal, side population and multipotent adult stem cells. Bone marrow cells have been hypothesized as a third recruitment source in liver regeneration in addition to hepatocytes and endogenous liver stem cells. Consequently, attempts have been made to differentiate them into hepatic lineage for their subsequent use in hepatic cell therapy. The present article reviews the progress made in this field or research.


Assuntos
Hepatócitos/transplante , Transplante de Células-Tronco , Animais , Humanos
16.
Eur J Heart Fail ; 6(7): 877-82, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15556049

RESUMO

BACKGROUND: Proinflammatory cytokines are important mediators in heart failure (HF). Recently, urinary levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have been determined. AIMS: The purpose of this study was to measure the urinary levels of TNF-alpha and IL-6 receptors, sTNF-RI, sTNF-RII, sIL-6R, and the relationship with plasma levels and NYHA classes in HF. METHODS: Plasma and urine were collected from 114 HF patients and sTNF-RI, sTNF-RII and sIL-6R (ng/ml) were analyzed. RESULTS: For the whole population, plasma levels of sTNF-RI were 2.1+/-0.1, of sTNF-RII were 5.0+/-0.3 and of sIL-6R were 49.8+/-2.5. Urinary levels were: sTNF-RI, 2.8+/-0.5, r=0.5, p<0.001; sTNF-RII, 12.6+/-2.1, r=0.4, p<0.001; and sIL-6R, 4.2+/-0.4, NS. In NYHA III subjects, we found sTNF-RI, r=0.6, p<0.01, sTNF-RII, r=0.5, p<0.05, and sILR-6, r=0.5, p<0.05. Both plasma TNF receptors and urinary levels of sTNF-RII were higher in patients in a more severe NYHA class (p<0.05). CONCLUSIONS: Urine is a good environment to study sTNF-RI and sTNF-RII, and this fact has diagnostic and prognostic implications. Plasma and urinary levels of TNF receptors showed a fair correlation, which was increased in higher NYHA classes. Plasma and urinary levels of sIL6R showed a good correlation in NYHA III. The TNF receptor levels in urine increased in patients with more severe HF.


Assuntos
Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/urina , Receptores de Interleucina-6/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Idoso , Biomarcadores/sangue , Biomarcadores/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos de Pesquisa , Índice de Gravidade de Doença , Solubilidade
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