RESUMO
Infection alters the expression of transporters that mediate the placental exchange of xenobiotics, lipids and cytokines. We hypothesized that lipopolysaccharide (LPS) modifies the expression of placental transport systems and lipid homeostasis. LPS (150 µg/kg; i.p.) treatments were administered for 4 h or 24 h, animals were euthanized at gestational days (GD) 15.5 or 18.5, and maternal blood, fetuses and placentae were collected. Increased rates of fetal demise were observed at GD15.5 following LPS treatment, whereas at GD18.5, high rates of early labour occurred and were associated with distinct proinflammatory responses. Lipopolysaccharide did not alter ATP-binding cassette (ABC) transporter mRNA expression but decreased fatty acid binding protein associated with plasma membrane (Fabppm) at GD15.5 (LPS-4 h) and increased fatty acid translocase (Fat/Cd36) mRNA at GD18.5 (LPS-4 h). At the protein level, breast cancer-related protein (Bcrp) and ABC sub-family G member 1 (Abcg1) levels were decreased in the placental labyrinth zone (Lz) at GD15.5, whereas P-glycoprotein (P-gp) and Bcrp Lz-immunostaining was decreased at GD18.5. In the placental junctional zone (Jz), P-gp, Bcrp and Abcg1 levels were higher at GD18.5. Specific maternal plasma and placental changes in triacylglycerol, free fatty acid, cholesterol, cholesterol ester and monoacylglycerol levels were detected in a gestational age-dependent manner. In conclusion, LPS-increased risk of fetal death and early labour were associated with altered placental ABC and lipid transporter expression and deranged maternal plasma and placental lipid homeostasis. These changes may potentially modify fetal xenobiotic exposure and placental lipid exchange in cases of bacterial infection.
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INTRODUCTION: Hepatocellular carcinoma is the most common liver malignancy and the third leading cause of cancer death worldwide. One crucial limitation in the pharmacotherapy for this tumour is its chemotherapy-resistant nature produced by the overexpression of several members of the ATP-binding cassette protein family that efflux drugs out of cells, as observed with the breast cancer resistant protein (BCRP). OBJECTIVES: This study aimed to assess the ability of Pluronic® F127 to reverse the multidrug resistance phenotype in two human hepatocellular cell lines. METHODS: PLC/PRF/5 and SKHep1 cells were exposed to Pluronic® F127 at several concentrations. The effect of F127 on BCRP expression (mRNA and protein), mitochondrial transmembrane potential and cell hypodiploidy was assessed. Finally, the effect of this copolymer on cytotoxicity of doxorubicin in both hepatoma cell lines was investigated, as expressed by its reverse resistance index. KEY FINDINGS: It was demonstrated that F127 in both cell lines contributes to chemosensitization, as shown by BCRP down-regulation, an altered mitochondrial transmembrane potential and hypodiploidy and reverse resistance index values. A remarkable dependence of these effects significantly correlated with the copolymer concentration. CONCLUSIONS: These findings further uncover the potential usefulness of this copolymer as multidrug resistance reversal agent, increasing the efficacy of cancer therapies.
Assuntos
Doxorrubicina/sangue , Doxorrubicina/farmacologia , Poloxâmero/química , Polietilenos/química , Polipropilenos/química , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Potencial da Membrana Mitocondrial/efeitos dos fármacosRESUMO
ATP binding cassette (ABC) transporters are transmembrane proteins expressed in secretory epithelia like the liver, kidneys and intestine, in the epithelia exhibiting barrier function such as the blood-brain barrier and placenta, and to a much lesser extent, in tissues like reproductive organs, lungs, heart and pancreas, among others. They regulate internal distribution of endogenous metabolites and xenobiotics including drugs of therapeutic use and also participate in their elimination from the body. We here describe the function and regulation of ABC transporters in the heart and small intestine, as examples of extrahepatic tissues, in which ABC proteins play clearly different roles. In the heart, they are involved in tissue pathogenesis as well as in protecting this organ against toxic compounds and druginduced oxidative stress. The small intestine is highly exposed to therapeutic drugs taken orally and, consequently, ABC transporters localized on its surface strongly influence drug absorption and pharmacokinetics. Examples of the ABC proteins currently described are Multidrug Resistance-associated Proteins 1 and 2 (MRP1 and 2) for heart and small intestine, respectively, and P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) for both organs.
Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Intestino Delgado/metabolismo , Fígado/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Carcinoma Hepatocelular/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Miocárdio/metabolismo , Proteínas de Neoplasias/metabolismo , Estresse OxidativoRESUMO
Nanotechnology has recently emerged as a promising tool in biomedicine research. An important branch of nanotechnology is drug delivery and drug targeting using a wide range of biomaterials with promising potential applications in cancer research. The aim of this review is to provide an overview of the evolution of nanotechnology in cancer therapy, exemplified by a myriad of applications in drug delivery, tumor targeting and reversal of ATP-binding cassette drug transporter-mediated multidrug resistance (MDR) in cancer cells by the biomaterials used in nanoformulations. Special attention will be focused on liver cancer, especially, on hepatocellular carcinoma, which is among the malignancies with the poorest prognosis due to its extremely "difficult-to-treat" nature related to its high recurrence rate and MDR phenotype.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/terapia , Animais , Resistencia a Medicamentos Antineoplásicos , Humanos , Nanomedicina/métodos , Nanotecnologia/métodosRESUMO
Multidrug resistance-associated protein 2 (MRP2) is a multi-specific organic anion transporter predominantly expressed in the canalicular membrane of hepatocytes, epithelial cells from gallbladder and apical membranes of proximal tubular kidney epithelium whereas multidrug resistance-associated protein 3 (MRP3) is present in the basolateral membrane of hepatocytes and cholangiocytes. This study aims to detect the expression of these transporters in hepatocellular carcinoma (HCC) and in cholangiocarcinoma (CC), searching for evidences for future studies on differential diagnosis and on clinical essays. The immunohistochemical reactivity (IHC) of these transporters was assessed in tissue microarrays of 80 HCC and 56 CC cases using monoclonal antibodies and compared with anatomopathological (AP) variables. The positivity of MRP2 was observed in 92.3% of HCC and in 96.3% of CC. The detection of high MRP2 expression in HCC was not significantly different (p > 0.05) according to the size, number of nodules architectural pattern and growth pattern of HCC and CC. Regarding histological grades, 22/22 well moderately differentiated HCC versus 50/56 poorly differentiated HCC were positive for MRP2. A trend for lower expression in poor differentiation HCC was found. And 50/50 well/moderately differentiated CC versus 2/4 poorly/undifferentiated CC were positive for MRP2. This result showed a reduced expression (p = 0,0004) in poorly differentiated CC. MRP3 positivity was observed in 18.8% of HCC and was not significantly different according to AP parameters. MRP3 was expressed in 44.5% CC, with a trend for lower expression in less differentiated CC and significantly lower rates in the ductular histological subtype (p = 0.023). The high expression of MRP2 in HCC and in CC is conserved regardless most of the anatomopathological parameters, except for a trend of lower expression in less differentiated HCC and CC. The observation of lower MRP3 expression in less differentiated CC and, especially, in the histological subtype with expression of hepatic progenitor cell phenotypes leads to future opportunities to evaluate the expression of this marker in cholangiocarcinomas.
Assuntos
Neoplasias dos Ductos Biliares/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Colangiocarcinoma/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/patologia , Carcinoma Hepatocelular/patologia , Colangiocarcinoma/patologia , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Proteína 2 Associada à Farmacorresistência Múltipla , PrognósticoRESUMO
Liver transporters play an important role in the pharmacokinetics and disposition of pharmaceuticals, environmental contaminants, and endogenous compounds. Among them, the family of ATP-Binding Cassette (ABC) transporters is the most important due to its role in the transport of endo- and xenobiotics. The ABCC sub-family is the largest one, consisting of 13 members that include the cystic fibrosis conductance regulator (CFTR/ABCC7); the sulfonylurea receptors (SUR1/ABCC8 and SUR2/ABCC9) and the multidrug resistanceassociated proteins (MRPs). The MRP-related proteins can collectively confer resistance to natural, synthetic drugs and their conjugated metabolites, including platinum-containing compounds, folate anti-metabolites, nucleoside and nucleotide analogs, among others. MRPs can be also catalogued into "long" (MRP1/ABCC1, -2/C2, -3/C3, -6/C6, and -7/C10) and "short" (MRP4/C4, -5/C5, -8/C11, -9/C12, and -10/C13) categories. While MRP2/ABCC2 is expressed in the canalicular pole of hepatocytes, all others are located in the basolateral membrane. In this review, we summarize information from studies examining the changes in expression and regulation of the basolateral hepatic transporter MPR3/ABCC3 by xenobiotics and during various pathophysiological conditions. We also focus, primarily, on the consequences of such changes in the pharmacokinetic, pharmacodynamic and/or toxicity of different drugs of clinical use transported by MRP3.
Assuntos
Fígado/efeitos dos fármacos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Xenobióticos/farmacologia , Xenobióticos/farmacocinética , Sítios de Ligação , Humanos , Fígado/metabolismo , Hepatopatias/metabolismo , Proteína 2 Associada à Farmacorresistência MúltiplaRESUMO
Bacterial ATP-binding cassette (ABC) transporters play a crucial role in the physiology and pathogenicity of different bacterial species. Components of ABC transporters have also been tested as target antigens for the development of vaccines against different bacterial species, such as those belonging to the Streptococcus genus. Streptococcus mutans is the etiological agent of dental caries, and previous studies have demonstrated that deletion of the gene encoding PstS, the substrate-binding component of the phosphate uptake system (Pst), reduced the adherence of the bacteria to abiotic surfaces. In the current study, we generated a recombinant form of the S. mutans PstS protein (rPstS) with preserved structural features, and we evaluated the induction of antibody responses in mice after sublingual mucosal immunization with a formulation containing the recombinant protein and an adjuvant derived from the heat-labile toxin from enterotoxigenic Escherichia coli strains. Mice immunized with rPstS exhibited systemic and secreted antibody responses, measured by the number of immunoglobulin A-secreting cells in draining lymph nodes. Serum antibodies raised in mice immunized with rPstS interfered with the adhesion of bacteria to the oral cavity of naive mice challenged with S. mutans. Similarly, mice actively immunized with rPstS were partially protected from oral colonization after challenge with the S. mutans NG8 strain. Therefore, our results indicate that S. mutans PstS is a potential target antigen capable of inducing specific and protective antibody responses after sublingual administration. Overall, these observations raise interesting perspectives for the development of vaccines to prevent dental caries.
Assuntos
Anticorpos Antibacterianos/sangue , Cárie Dentária/prevenção & controle , Imunização/métodos , Boca/microbiologia , Proteínas de Ligação a Fosfato/imunologia , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/imunologia , Adjuvantes Imunológicos , Administração Sublingual , Animais , Antígenos de Bactérias/imunologia , Aderência Bacteriana , Vacinas Bacterianas/imunologia , Cárie Dentária/microbiologia , Escherichia coli Enterotoxigênica/química , Feminino , Imunidade nas Mucosas , Imunoglobulina A/análise , Camundongos , Proteínas de Ligação a Fosfato/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Saliva/imunologiaRESUMO
PURPOSES: To determine the basic expression of ABC transporters in an epithelial ovarian cancer cell line, and to investigate whether low concentrations of acetaminophen and ibuprofen inhibited the growth of this cell line in vitro. METHODS: TOV-21 G cells were exposed to different concentrations of acetaminophen (1.5 to 15 μg/mL) and ibuprofen (2.0 to 20 μg/mL) for 24 to 48 hours. The cellular growth was assessed using a cell viability assay. Cellular morphology was determined by fluorescence microscopy. The gene expression profile of ABC transporters was determined by assessing a panel including 42 genes of the ABC transporter superfamily. RESULTS: We observed a significant decrease in TOV-21 G cell growth after exposure to 15 μg/mL of acetaminophen for 24 (p=0.02) and 48 hours (p=0.01), or to 20 μg/mL of ibuprofen for 48 hours (p=0.04). Assessing the morphology of TOV-21 G cells did not reveal evidence of extensive apoptosis. TOV-21 G cells had a reduced expression of the genes ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 and ABCE1 within the ABC transporter superfamily. CONCLUSIONS: This study provides in vitro evidence of inhibitory effects of growth in therapeutic concentrations of acetaminophen and ibuprofen on TOV-21 G cells. Additionally, TOV-21 G cells presented a reduced expression of the ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 and ABCE1 transporters. .
OBJETIVOS: Determinar a expressão básica dos transportadores ABC em uma linhagem celular do câncer epitelial de ovário, e investigar se o acetaminofen e o ibuprofeno em baixas concentrações são capazes de inibir o crescimento desta linhagem celular in vitro. MÉTODOS: A linhagem celular TOV-21 G foi exposta a diferentes concentrações de acetaminofen (1,5 a 15 µg/mL) e ibuprofeno (2,0 a 20 µg/mL), de 24 a 48 horas. O crescimento celular foi avaliado utilizando-se um ensaio de viabilidade celular. A morfologia celular foi determinada por meio da microscopia de fluorescência. O perfil de expressão gênica foi estabelecido por um painel de 42 genes da superfamília de transportadores ABC. RESULTADOS: Observou-se um decréscimo significativo no crescimento das células TOV-21 G expostas a 15 µg/mL de acetaminofen durante 24 (p=0,02) e 48 horas (p=0,01), ou a 20 µg/mL de ibuprofeno por 48 horas (p=0,04). Ao avaliar a morfologia das células cultivadas, não foi observada evidência de apoptose extensiva. A linhagem de células estudada subexpressa os genes de ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 e ABCE1 na superfamília de transportadores ABC. CONCLUSÕES: Este estudo fornece evidências in vitro referentes aos efeitos inibidores do crescimento de concentrações terapêuticas do acetaminofen e ibuprofeno na linhagem celular testada. Além disso, as células TOV-21 G apresentaram uma expressão reduzida de genes dos transportadores ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 e ABCE1. .
Assuntos
Humanos , Feminino , Acetaminofen/farmacologia , Transportadores de Cassetes de Ligação de ATP/genética , Proliferação de Células/efeitos dos fármacos , Ibuprofeno/farmacologia , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Transcriptoma/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
The pregnane X receptor (PXR) (nuclear receptor NR1I2) is a ligand activated transcription factor, mediating responses to diverse xenobiotic and endogenous chemicals. The properties of PXR in fish are not fully understood. Here we report on cloning and characterization of full-length PXR of zebrafish, Danio rerio, and pxr expression in vivo. Initial efforts gave a cDNA encoding a 430 amino acid protein identified as zebrafish pxr by phylogenetic and synteny analysis. The sequence of the cloned Pxr DNA binding domain (DBD) was highly conserved, with 74% identity to human PXR-DBD, while the ligand-binding domain (LBD) of the cloned sequence was only 44% identical to human PXR-LBD. Sequence variation among clones in the initial effort prompted sequencing of multiple clones from a single fish. There were two prominent variants, one sequence with S183, Y218 and H383 and the other with I183, C218 and N383, which we designate as alleles pxr*1 (nr1i2*1) and pxr*2 (nr1i2*2), respectively. In COS-7 cells co-transfected with a PXR-responsive reporter gene, the full-length Pxr*1 (the more common variant) was activated by known PXR agonists clotrimazole and pregnenolone 16α-carbonitrile but to a lesser extent than the full-length human PXR. Activation of full-length Pxr*1 was only 10% of that with the Pxr*1 LBD. Quantitative real time PCR analysis showed prominent expression of pxr in liver and eye, as well as brain and intestine of adult zebrafish. The pxr was expressed in heart and kidney at levels similar to that in intestine. The expression of pxr in liver was weakly induced by ligands for mammalian PXR or constitutive androstane receptor (NR1I3). The results establish a foundation for PXR studies in this vertebrate model. PXR allelic variation and the differences between the full-length PXR and the LBD in reporter assays have implications for assessing the action of PXR ligands in zebrafish.
Assuntos
Alelos , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Peixe-Zebra/genética , Animais , Encéfalo/metabolismo , Receptor Constitutivo de Androstano , Olho/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Ordem dos Genes , Fígado/metabolismo , Masculino , Dados de Sequência Molecular , Fenobarbital/farmacologia , Filogenia , Receptor de Pregnano X , Ligação Proteica , Piridinas/farmacologia , Poluentes Químicos da Água/farmacologia , Peixe-Zebra/classificação , Peixe-Zebra/metabolismoRESUMO
In the struggle for life, the capacity of microorganisms to synthesize and secrete toxic compounds (inhibiting competitors) plays an important role in successful survival of these species. This ability must come together with the capability of being unaffected by these same compounds. Several mechanisms are thought to avoid the toxic effects. One of them is toxin extrusion from the intracellular environment to the outside vicinity, using special transmembrane proteins, referred to as transporters. These proteins are also important for other reasons, since most of them are involved in nutrient uptake and cellular excretion. In cancer cells and in pathogens, and particularly in fungi, some of these proteins have been pointed out as responsible for an important phenotype known as multidrug resistance (MDR). In the present study, we tried to identify in the Paracoccidioides brasiliensis transcriptome, transporter-ortholog genes from the two major classes: ATP binding cassette and major facilitator superfamily transporter. We found 22 groups with good similarity with other fungal ATP binding cassette transporters, and four Paracoccidioides brasilienses assembled expressed sequence tags that probably code for major facilitator superfamily proteins. We also focused on fungicide resistance orthologs already characterized in other pathogenic fungi. We were able to find homologs to C. albicans CDR1, CDR2, and MDR1, Saccharomyces cerevisiae PDR5 and Aspergillus AtrF genes, all of them related to azole resistance. As current treatment for paracoccidioidomycosis mainly uses azole derivatives, the presence of these genes can be postulated to play a similar role in P. brasiliensis, warning us for the possibility of resistant isolate emergence.