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1.
J Endocrinol Invest ; 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38733428

RESUMO

PURPOSE: Information on the general health of transgender and gender diverse (TGD) individuals continues to be lacking. To bridge this gap, the National Institute of Health in Italy together with the National Office against Racial Discriminations, clinical centres, and TGD organizations carried out a cross-sectional study to define the sociodemographic profile, health-related behaviours, and experiences of healthcare access in Italian TGD adult population. METHODS: A national survey was conducted by Computer-Assisted Web Interviewing (CAWI) technique. Collected data were compared within the TGD subgroups and between TGD people and the Italian general population (IGP). RESULTS: TGD respondents were 959: 65% assigned female at birth (AFAB) and 35% assigned male at birth (AMAB). 91.8% and 8.2% were binary and non-binary TGD respondents, respectively. More than 20% of the TGD population reported to be unemployed with the highest rate detectable in AMAB and non-binary people. Cigarette smoking and binge drinking were higher in the TGD population compared with IGP (p < 0.05), affecting TGD subgroups differently. A significant lower percentage of AFAB TGD people reported having had screening for cervical and breast cancer in comparison with AFAB IGP (p < 0.0001, in both cases). Over 40% was the percentage of AFAB and non-binary TGD people accessing healthcare who felt discriminated against because of their gender identity. CONCLUSIONS: Our results are a first step towards a better understanding of the health needs of TGD people in Italy in order to plan the best policy choices for a more inclusive public health.

2.
J Endocrinol Invest ; 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372939

RESUMO

BACKGROUND: Despite the increasing interest in transgender health research, to date little is known about the size of the transgender and gender diverse (TGD) population. METHODS: A web-based questionnaire survey was developed, including a collection of socio-demographic characteristics and disseminated online through social media. Gender incongruence was evaluated by using a 2-item approach assessing gender recorded at birth and gender identity. The primary objective of the present population-based study was to estimate the proportion of TGD people across ages among a large sample of people who answered a web-based survey. The secondary endpoints were to identify gender-affirming needs and possible barriers to healthcare access. RESULTS: A total of 19,572 individuals participated in the survey, of whom 7.7% reported a gender identity different from the sex recorded at birth. A significantly higher proportion of TGD people was observed in the youngest group of participants compared with older ones. Among TGD people who participated in the study, 58.4% were nonbinary, and 49.1% experienced discrimination in accessing health care services. Nonbinary TGD participants reported both the need for legal name and gender change, along with hormonal and surgical interventions less frequently compared to binary persons. CONCLUSIONS: Being TGD is not a marginal condition In Italy. A large proportion of TGD persons may not need medical and surgical treatments. TGD people often experience barriers to healthcare access relating to gender identity.

3.
Oncogene ; 34(40): 5163-74, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25659576

RESUMO

An inverted pH gradient across the cell membranes is a typical feature of malignant cancer cells that are characterized by extracellular acidosis and cytosol alkalization. These dysregulations are able to create a unique milieu that favors tumor progression, metastasis and chemo/immune-resistance traits of solid tumors. A key event mediating tumor cell pH alterations is an aberrant activation of ion channels and proton pumps such as (H+)-vacuolar-ATPase (V-ATPase). TM9SF4 is a poorly characterized transmembrane protein that we have recently shown to be related to cannibal behavior of metastatic melanoma cells. Here, we demonstrate that TM9SF4 represents a novel V-ATPase-associated protein involved in V-ATPase activation. We have observed in HCT116 and SW480 colon cancer cell lines that TM9SF4 interacts with the ATP6V1H subunit of the V-ATPase V1 sector. Suppression of TM9SF4 with small interfering RNAs strongly reduces assembly of V-ATPase V0/V1 sectors, thus reversing tumor pH gradient with a decrease of cytosolic pH, alkalization of intracellular vesicles and a reduction of extracellular acidity. Such effects are associated with a significant inhibition of the invasive behavior of colon cancer cells and with an increased sensitivity to the cytotoxic effects of 5-fluorouracil. Our study shows for the first time the important role of TM9SF4 in the aberrant constitutive activation of the V-ATPase, and the development of a malignant phenotype, supporting the potential use of TM9SF4 as a target for future anticancer therapies.


Assuntos
Neoplasias do Colo/patologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Proteínas de Membrana/metabolismo , Invasividade Neoplásica/patologia , ATPases Vacuolares Próton-Translocadoras/metabolismo , Western Blotting , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Concentração de Íons de Hidrogênio , Imunoprecipitação , Microscopia Confocal , Reação em Cadeia da Polimerase , Transfecção
5.
Cell Death Dis ; 4: e863, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-24136227

RESUMO

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) acts as an apoptosis inducer for cancer cells sparing non-tumor cell targets. However, several phase I/II clinical trials have shown limited benefits of this molecule. In the present work, we investigated whether cell susceptibility to TRAIL ligation could be due to the presence of TRAIL death receptors (DRs) 4 and 5 in membrane microdomains called lipid rafts. We performed a series of analyses, either by biochemical methods or fluorescence resonance energy transfer (FRET) technique, on normal cells (i.e. lymphocytes, fibroblasts, endothelial cells), on a panel of human cancer B-cell lines as well as on CD19(+) lymphocytes from patients with B-chronic lymphocytic leukemia, treated with different TRAIL ligands, that is, recombinant soluble TRAIL, specific agonistic antibodies to DR4 and DR5, or CD34(+) TRAIL-armed cells. Irrespective to the expression levels of DRs, a molecular interaction between ganglioside GM3, abundant in lymphoid cells, and DR4 was detected. This association was negligible in all non-transformed cells and was strictly related to TRAIL susceptibility of cancer cells. Interestingly, lipid raft disruptor methyl-beta-cyclodextrin abrogated this susceptibility, whereas the chemotherapic drug perifosine, which induced the recruitment of TRAIL into lipid microdomains, improved TRAIL-induced apoptosis. Accordingly, in ex vivo samples from patients with B-chronic lymphocytic leukemia, the constitutive embedding of DR4 in lipid microdomains was associated per se with cell death susceptibility, whereas its exclusion was associated with TRAIL resistance. These results provide a key mechanism for TRAIL sensitivity in B-cell malignances: the association, within lipid microdomains, of DR4 but not DR5, with a specific ganglioside, that is the monosialoganglioside GM3. On these bases we suggest that lipid microdomains could exert a catalytic role for DR4-mediated cell death and that an ex vivo quantitative FRET analysis could be predictive of cancer cell sensitivity to TRAIL.


Assuntos
Apoptose/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Microdomínios da Membrana/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Anticorpos/farmacologia , Antígenos CD34/metabolismo , Linhagem Celular Transformada , Linhagem Celular Tumoral , Separação Celular , Citometria de Fluxo , Humanos , Microdomínios da Membrana/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Solubilidade
6.
Neurogastroenterol Motil ; 25(12): 984-e777, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24118564

RESUMO

BACKGROUND: Lactobacillus species might positively affect gastrointestinal motility. These Gram-positive bacteria bind Toll-like receptor 2 (TLR2) that elicits anti-inflammatory activity and exerts protective effects on damage induced by lipopolysaccharide (LPS). Whether such effect occurs in gastrointestinal smooth muscle has not been established yet. Aim of this study was to characterize the effects of Lactobacillus rhamnosus GG (LGG) and of supernatants harvested from LGG cultures on human colonic smooth muscle and to explore their protective activity against LPS-induced myogenic morpho-functional alterations. METHODS: The effects of LGG (ATCC 53103 strain) and of supernatants have been tested on both human colonic smooth muscle strips and isolated cells in the absence or presence of LPS obtained from a pathogenic strain of Escherichia coli. Their effects on myogenic morpho-functional properties, on LPS-induced NFκB activation, and on cytokine production have been evaluated. Toll-like receptor 2 expression has been analyzed by qPCR and flow cytometry. KEY RESULTS: Lactobacillus rhamnosus GG exerted negligible transient effects per se whereas it was capable of activating an intrinsic myogenic response counteracting LPS-induced alterations. In particular, both LGG and supernatants significantly reduced the LPS-induced morpho-functional alterations of muscle cells, i.e. cell shortening and inhibition of contractile response. They also hindered LPS-induced pro-inflammatory effects by decreasing pro-inflammatory transcription factor NFκB activation and pro-inflammatory cytokine IL-6 secretion, and restored the secretion levels of anti-inflammatory cytokine IL10. CONCLUSIONS & INFERENCES: Taken together these data demonstrate that LGG protects human colonic smooth muscle from LPS-induced myogenic damage and might be beneficial on intestinal motor disorders due to bacterial infection.


Assuntos
Colo/microbiologia , Lacticaseibacillus rhamnosus , Lipopolissacarídeos/toxicidade , Músculo Liso/microbiologia , Probióticos/farmacologia , Células Cultivadas , Colo/efeitos dos fármacos , Motilidade Gastrointestinal , Humanos , Músculo Liso/efeitos dos fármacos
7.
Curr Mol Med ; 13(4): 499-513, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23438904

RESUMO

Sex/gender differences in terms of incidence, prevalence, age at onset and severity have been documented for several complex adulthood diseases. However, several pediatric diseases also displayed a gender disparity. Unfortunately, epidemiologic studies investigating gender disparity in pediatric age show dissimilar results often depending on the spatial and temporal issues, to considerable regional environmental variations, to social conditions or to infectious agent virulence. Anyway, studies over time showed that gender disparity in childhood mortality and morbidity may be narrow in some pathological conditions whereas in other severe diseases, e.g. sepsis, some cancers and some immune disorders, the disproportion was found as significant. In this work we briefly review literature data dealing with sex/gender differences in morbidity and mortality observed during the pediatric age. In particular, communicable and non-communicable diseases, including cancer, have been considered. The possible mechanisms underlining these differences, e.g. hormonal and epigenetic, are also discussed. The analysis of literature available as concerns pediatric age seems to underline that gender differences start very early in human beings and that hormones as well as gene expression in XX and XY cells can play a role. A reappraisal of the gender issue in pediatric research could thus be pivotal: it might contribute to the improvement of diagnostic and therapeutic strategies as well as to the improvement of the appropriateness of the cures.


Assuntos
Doença/classificação , Pediatria , Fatores Sexuais , Pré-Escolar , Doenças Transmissíveis , Anormalidades Congênitas , Feminino , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Masculino
8.
Neurobiol Aging ; 33(4): 753-66, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20594618

RESUMO

It has become evident that an autoimmune component could play a role in Alzheimer's disease (AD) onset and/or progression. The aim of this study was to identify neuronal antigenic targets specifically recognized by serum autoantibodies and to investigate their cellular effects and their possible pathogenetic role. We identified, by an immunoproteomic approach using mouse brain proteins, the adenosine triphosphate (ATP) synthase ß subunit as a new autoantigen in AD. Using an ELISA assay we found that serum anti-ATP synthase autoantibodies were present in 38% of patients with AD, but in no age-matched healthy subjects or in patients with Parkinson's disease or atherosclerosis. Analytical cytology studies, using SH-SY5Y neuroblastoma cell line, showed that ATP synthase autoantibodies were capable of inducing the inhibition of ATP synthesis, alterations of mitochondrial homeostasis and cell death by apoptosis. These findings suggest that autoantibodies specific to ATP synthase can exert a pathogenetic role via a mechanism that brings into play the impairment of the extracellular ATP homeostasis and the alteration of mitochondrial function triggering cell death by apoptosis.


Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/imunologia , Autoanticorpos/sangue , ATPases Mitocondriais Próton-Translocadoras/imunologia , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/líquido cefalorraquidiano , Animais , Anexina A5/metabolismo , Apoptose/efeitos dos fármacos , Autoanticorpos/farmacologia , Encéfalo/metabolismo , Linhagem Celular Tumoral , Eletroforese em Gel Bidimensional , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lúpus Eritematoso Sistêmico/sangue , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Neuroblastoma/patologia , Alinhamento de Sequência , Fatores de Tempo , Adulto Jovem
9.
Cell Death Differ ; 17(6): 1047-58, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20075943

RESUMO

It was shown that receptor-mediated apoptosis involves a cascade of subcellular events including alterations of mitochondria. Loss of mitochondrial membrane potential that follows death receptor ligation allows the release of apoptogenic factors that result in apoptosis execution. Further important mitochondrial changes have been observed in this regard: mitochondrial remodeling and fission that appear as prerequisites for the occurrence of the cell death program. As it was observed that lipid rafts, glycosphingolipid-enriched structures, can participate in the apoptotic cascade being recruited to the mitochondria under receptor-mediated proapoptotic stimulation, we decided to analyze the possible implication of these microdomains in mitochondrial fission. We found that molecules involved in mitochondrial fission processes are associated with these domains. In particular, although hFis1 was constitutively included in mitochondrial raft-like domains, dynamin-like protein 1 was recruited to these domains on CD95/Fas triggering. Accordingly, the disruption of rafts, for example, by inhibiting ceramide synthase, leads to the impairment of fission molecule recruitment to the mitochondria, reduction of mitochondrial fission and a significant reduction of apoptosis. We hypothesize that under apoptotic stimulation the recruitment of fission-associated molecules to the mitochondrial rafts could have a role in the morphogenetic changes leading to organelle fission.


Assuntos
Apoptose , Microdomínios da Membrana/química , Mitocôndrias/ultraestrutura , Membranas Mitocondriais/química , Proteínas Mitocondriais/análise , Células Cultivadas , Centrifugação com Gradiente de Concentração , Dinaminas , Inibidores Enzimáticos/farmacologia , Fumonisinas/farmacologia , GTP Fosfo-Hidrolases/análise , Gangliosídeos/análise , Humanos , Proteínas de Membrana/análise , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/análise , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Octoxinol , Oxirredutases/antagonistas & inibidores , Interferência de RNA , Receptor fas/metabolismo
10.
Cell Death Differ ; 16(11): 1480-92, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19644512

RESUMO

In this study we provide in vitro and in vivo evidence showing that the protein disulphide isomerase (PDI) activity of type 2 transglutaminase (TG2) regulates the correct assembly and function of the mitochondrial ADP/ATP transporter adenine nucleotide translocator 1 (ANT1). We demonstrate, by means of biochemical and morphological analyses, that ANT1 and TG2 physically interact in the mitochondria. Under physiological conditions, TG2's PDI activity regulates the ADP/ATP transporter function by controlling the oligomerization of ANT1. In fact, mitochondria isolated from hearts of TG2(-/-) mice exhibit increased polymerization of ANT1, paralleled by an enhanced ADP/ATP carrier activity, as compared to mitochondria belonging to TG2(+/+) mice. Interestingly, upon cell-death induction, ANT1 becomes a substrate for TG2's cross-linking activity and the lack of TG2 results in a reduction of apoptosis as well as in a marked sensitivity to the ADP/ATP exchange inhibition by atractyloside. These findings suggest a complex TG2-dependent regulation of the ADP/ATP transporter and reveal new important avenues for its potential applications in the treatment of some mitochondrial-dependent diseases, including cardiovascular and neurodegenerative diseases.


Assuntos
Translocador 1 do Nucleotídeo Adenina/metabolismo , Apoptose , Proteínas de Ligação ao GTP/metabolismo , Mitocôndrias Cardíacas/metabolismo , Transglutaminases/metabolismo , Translocador 1 do Nucleotídeo Adenina/análise , Animais , Proteínas de Ligação ao GTP/análise , Proteínas de Ligação ao GTP/genética , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 2 Glutamina gama-Glutamiltransferase , Transglutaminases/análise , Transglutaminases/genética , Proteína X Associada a bcl-2/metabolismo
11.
Curr Pharm Des ; 14(3): 245-52, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18220835

RESUMO

The term self-cannibalism, or autophagy, was coined to describe the ability of the cells to cannibalize their own damaged organelles or proteins. It was morphologically described as the presence of double-membraned autophagic vesicles filled with diverse cellular materials or debris inside the cells. Hence, more recently, the presence of autophagic vacuoles has been associated with cell survival, including cell senescence and cancer and appears to be activated by nutrient deprivation. The occurrence of autophagic processes can also lead, as final event, to the death of the cell. In this review we summarize the results reported in literature on a phagic process that appears to be related to self-cannibalism: the xeno-cannibalism. This was described as the ability of certain cells, e.g. metastatic cells, to cannibalize their siblings as well as cells from the immune system. Interestingly, metastatic tumor cells are also able to engulf and digest living cells, including autologous lymphocytes that should kill them, i.e. CD8(+) cytotoxic lymphocytes. This can represent a formidable opportunity for metastatic cells to survive in adverse conditions such as those they encounter in their "journey" towards the target organ to establish a colony. Altogether these findings seem to suggest a pathogenetic role for cannibalic behavior in human pathology and point at this surprising cellular aggressiveness as an innovative pharmacological target in the clinical management of metastatic disease.


Assuntos
Autofagia/fisiologia , Sobrevivência Celular/fisiologia , Neoplasias/metabolismo , Senescência Celular/fisiologia , Sistemas de Liberação de Medicamentos , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/metabolismo , Modelos Biológicos , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/fisiopatologia , Neoplasias/tratamento farmacológico , Vacúolos/metabolismo
12.
Cell Death Differ ; 14(3): 453-61, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17008914

RESUMO

Subcellular organelles such as mitochondria, endoplasmic reticulum (ER) and the Golgi complex are involved in the progression of the cell death programme. We report here that soon after ligation of Fas (CD95/Apo1) in type II cells, elements of the Golgi complex intermix with mitochondria. This mixing follows centrifugal dispersal of secretory membranes and reflects a global alteration of membrane traffic. Activation of apical caspases is instrumental for promoting the dispersal of secretory organelles, since caspase inhibition blocks the outward movement of Golgi-related endomembranes and reduces their mixing with mitochondria. Caspase inhibition also blocks the FasL-induced secretion of intracellular proteases from lysosomal compartments, outlining a novel aspect of death receptor signalling via apical caspases. Thus, our work unveils that Fas ligand-mediated apoptosis induces scrambling of mitochondrial and secretory organelles via a global alteration of membrane traffic that is modulated by apical caspases.


Assuntos
Complexo de Golgi/metabolismo , Membranas Intracelulares/metabolismo , Mitocôndrias/metabolismo , Receptores de Morte Celular/metabolismo , Receptor fas/metabolismo , Apoptose , Caspases/metabolismo , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Proteína Ligante Fas/metabolismo , Células HeLa , Humanos , Células Jurkat , Ligantes , Lisossomos/enzimologia , Organelas/metabolismo , Peptídeo Hidrolases/metabolismo , Transdução de Sinais
13.
Cell Death Differ ; 12 Suppl 1: 932-41, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15818415

RESUMO

Cytoskeletal components play a major role in the human immunodeficiency virus-1 (HIV-1) infection. A wide variety of molecules belonging to the microfilament system, including actin filaments and actin binding proteins, as well as microtubules have a key role in regulating both cell life and death. Cell shape maintenance, cell polarity and cell movements as well as cytoplasmic trafficking of molecules determining cell fate, including apoptosis, are in fact instructed by the cytoskeleton components. HIV infection and viral particle production seem to be controlled by cytoskeleton as well. Furthermore, HIV-associated apoptosis failure can also be regulated by the actin network function. In fact, HIV protein gp120 is able to induce cytoskeleton-driven polarization, thus sensitizing T cells to CD95/Fas-mediated apoptosis. The microfilament system seems thus to be a sort of cytoplasmic supervisor of the viral particle, the host cell and the bystander cell's very fate.


Assuntos
Citoesqueleto de Actina/virologia , Apoptose , Produtos do Gene nef/fisiologia , Produtos do Gene tat/fisiologia , Produtos do Gene vpr/fisiologia , Proteína gp120 do Envelope de HIV/fisiologia , HIV-1/fisiologia , Linfócitos T/virologia , Proteínas Virais/fisiologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Animais , Produtos do Gene nef/farmacologia , Produtos do Gene tat/farmacologia , Produtos do Gene vpr/farmacologia , Proteína gp120 do Envelope de HIV/farmacologia , Humanos , Proteínas dos Microfilamentos/metabolismo , Microtúbulos/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Linfócitos T/ultraestrutura , Proteínas Virais/farmacologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana , Produtos do Gene tat do Vírus da Imunodeficiência Humana , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
14.
Cell Death Differ ; 11(5): 574-82, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-14739941

RESUMO

CD95(APO-1/Fas)-mediated apoptosis of bystander uninfected T cells exerts a major role in the HIV-1-mediated CD4+ T-cell depletion. HIV-1 gp120 has a key role in the induction of sensitivity of human lymphocytes to CD95-mediated apoptosis through its interaction with the CD4 receptor. Recently, we have shown the importance of CD95/ezrin/actin association in CD95-mediated apoptosis. In this study, we explored the hypothesis that the gp120-mediated CD4 engagement could be involved in the induction of susceptibility of primary human T lymphocytes to CD95-mediated apoptosis through ezrin phosphorylation and ezrin-to-CD95 association. Here, we show that gp120/IL-2 combined stimuli, as well as the direct CD4 triggering, on human primary CD4(+)T lymphocytes induced an early and stable ezrin activation through phosphorylation, consistent with the induction of ezrin/CD95 association and susceptibility to CD95-mediated apoptosis. Our results provide a new mechanism through which HIV-1-gp120 may predispose resting CD4(+)T cell to bystander CD95-mediated apoptosis and support the key role of ezrin/CD95 linkage in regulating susceptibility to CD95-mediated apoptosis.


Assuntos
Apoptose/fisiologia , Proteína gp120 do Envelope de HIV/toxicidade , Fosfoproteínas/metabolismo , Linfócitos T/metabolismo , Receptor fas/metabolismo , Apoptose/efeitos dos fármacos , Antígenos CD4/metabolismo , Proteínas do Citoesqueleto , Humanos , Interleucina-2/metabolismo , Ativação Linfocitária/fisiologia , Fosforilação
17.
Eur J Cell Biol ; 80(2): 187-95, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11302524

RESUMO

Cell volumes decreased in HeLa cells as a function of time after seeding during exponential growth. Cell volume distributions revealed the presence of two cell populations in all stages of growth. When cells approached confluence, the ratio of the two populations abruptly shifted towards that characterised by the smallest volume. Percentages of G1-, S- and G2 + M-phase cells were also measured and it was found that G1 frequency increased as a function of cell density during exponential growth. Intracellular sodium concentration, [Na]i was monitored by 23Na NMR in the presence of 5 mM dysprosium (III) tripolyphosphate. [Na]i increased from 22.8 to 59.0 mM in cells from the second to the seventh day after seeding. Treatment with lonidamine, an antitumoral drug that it is known to slow down cell growth by affecting aerobic glycolysis, produced a complete block of cell progression after a few days of treatment. The progression of cell volume distributions towards smaller volumes and the increase in internal sodium concentration as a function of time after seeding were also affected by the drug. These phenomena were related to the existence of a subpopulation of mitotically inactive G1-phase cells during exponential growth, pointing out that a density-dependent cellular mechanism regulates the cell cycling in HeLa cells.


Assuntos
Antineoplásicos/farmacologia , Indazóis/farmacologia , Sódio/metabolismo , Divisão Celular/efeitos dos fármacos , Tamanho Celular , Fase G1 , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Isótopos de Sódio
18.
Biochem J ; 355(Pt 3): 587-95, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11311119

RESUMO

Multidrug resistance caused by P-glycoprotein (P-170) is a phenomenon by which cells exposed to a single drug acquire resistance to other structurally and functionally unrelated drugs. This is a widespread phenomenon described in vivo in the management of infectious as well as non-infectious diseases. Several in vitro models have been developed in order to evaluate physiopathological properties of P-170. Among these are P-170-expressing variants of the human T-lymphoblastoid CEM cell line called VBL100. As a general rule, drug resistance normally results in resistance to apoptosis induction. By contrast, a paradoxical activity is exerted in this cell model by the cytokine tumour necrosis factor-alpha (TNF-alpha), which is capable of inducing apoptosis in P-170-expressing variants better than in wild-type (wt) cells. In the present study we partially address the mechanisms underlying this activity. In fact, the susceptibility of VBL100 cells to TNF-alpha appears to be specifically due to the depolarization of their mitochondrial membrane, a key factor for apoptotic induction. The same was observed with staurosporine, a specific mitochondrion-mediated proapoptotic chemical probe. Conversely, other proapoptotic stimuli, such as Fas/CD95 or the anti-cancer drug etoposide, did induce significant cell death in wild type cells only. Thus, schematically, mitochondrially dependent stimuli appeared to be more effective in VBL100-cell killing, while 'physiological' stimuli showed the opposite behaviour. Importantly, under steady-state conditions, VBL100 cells displayed per se a mitochondrial membrane hyperpolarization that appeared strictly related to their high susceptibility to specific apoptotic stimuli. In conclusion, the study of a well-established cell model such as that represented by the wt/VBL CEM lymphoid cell line seems to suggest that the multidrug resistance phenotype can specifically sensitize cells towards 'unphysiological', mitochondria-associated cell death cascade or, in the same fashion, it could shift cells from type I (mainly plasma membrane-associated) towards type II (mainly mitochondrial membrane-associated) phenotype.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Apoptose/fisiologia , Mitocôndrias/fisiologia , Citometria de Fluxo , Humanos , Membranas Intracelulares/fisiologia , Potenciais da Membrana , Permeabilidade , Células Tumorais Cultivadas
20.
Biochem Biophys Res Commun ; 279(2): 552-6, 2000 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-11118324

RESUMO

A key role has been proposed for reactive oxygen species (ROS) in chronic obstructive pulmonary disease (COPD). Aim of the present work was to evaluate possible implications of ROS in the integrity and function of the cell type mainly involved in oxygen uptake and delivery to the peripheral tissues: the erythrocyte. Red blood cells (RBCs) were thus collected from blood samples from COPD patients. Furthermore, blood samples from the same patients treated with the antioxidizing drug of widespread use in such disease i.e., N-acetylcysteine (NAC), were also considered. Morphometric and analytical cytology studies were then conducted. We report herein that: (i) alterations of RBC ultrastructure were detectable in RBCs from COPD patients, that (ii) relevant changes of spectrin cytoskeleton and glycophorin expression were also found and that (iii) NAC treatment was capable of significantly counteracting these changes. These results are consistent with a reappraisal of the role of RBCs in this disease.


Assuntos
Acetilcisteína/farmacologia , Eritrócitos/fisiologia , Pneumopatias Obstrutivas/sangue , Idoso , Eritrócitos/efeitos dos fármacos , Eritrócitos/ultraestrutura , Glicoforinas/metabolismo , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Espécies Reativas de Oxigênio/fisiologia , Valores de Referência
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