RESUMO
BACKGROUND: Quebec is one of the Canadian provinces with the highest rates of cancer incidence and prevalence. A study by the Rossy Cancer Network (RCN) of McGill university assessed six aspects of the patient experience among cancer patients and found that emotional support is the aspect most lacking. To improve this support, trained patient advisors (PAs) can be included as full-fledged members of the healthcare team, given that PA can rely on their knowledge with experiencing the disease and from using health and social care services to accompany cancer patients, they could help to round out the health and social care services offer in oncology. However, the feasibility of integrating PAs in clinical oncology teams has not been studied. In this multisite study, we will explore how to integrate PAs in clinical oncology teams and, under what conditions this can be successfully done. We aim to better understand effects of this PA intervention on patients, on the PAs themselves, the health and social care team, the administrators, and on the organization of services and to identify associated ethical and legal issues. METHODS/DESIGN: We will conduct six mixed methods longitudinal case studies. Qualitative data will be used to study the integration of the PAs into clinical oncology teams and to identify the factors that are facilitators and inhibitors of the process, the associated ethical and legal issues, and the challenges that the PAs experience. Quantitative data will be used to assess effects on patients, PAs and team members, if any, of the PA intervention. The results will be used to support oncology programs in the integration of PAs into their healthcare teams and to design a future randomized pragmatic trial to evaluate the impact of PAs as full-fledged members of clinical oncology teams on cancer patients' experience of emotional support throughout their care trajectory. DISCUSSION: This study will be the first to integrate PAs as full-fledged members of the clinical oncology team and to assess possible clinical and organizational level effects. Given the unique role of PAs, this study will complement the body of research on peer support and patient navigation. An additional innovative aspect of this study will be consideration of the ethical and legal issues at stake and how to address them in the health care organizations.
Assuntos
Oncologia , Equipe de Assistência ao Paciente , Canadá , Humanos , Avaliação de Resultados da Assistência ao Paciente , Quebeque/epidemiologiaRESUMO
BACKGROUND/OBJECTIVES: Maternal obesity increases the risk of poor pregnancy outcome including stillbirth, pre-eclampsia, fetal growth restriction and fetal overgrowth. These pregnancy complications are associated with dysfunctional syncytiotrophoblast, the transporting epithelium of the human placenta. Taurine, a ß-amino acid with antioxidant and cytoprotective properties, has a role in syncytiotrophoblast development and function and is required for fetal growth and organ development. Taurine is conditionally essential in pregnancy and fetal tissues depend on uptake of taurine from maternal blood. We tested the hypothesis that taurine uptake into placental syncytiotrophoblast by the taurine transporter protein (TauT) is lower in obese women (body mass index (BMI)⩾30 kg m(-)(2)) than in women of ideal weight (BMI 18.5-24.9 kg m(-)(2)) and explored potential regulatory factors. SUBJECTS/METHODS: Placentas were collected from term (37-42-week gestation), uncomplicated, singleton pregnancies from women with BMI 19-49 kg m(-)(2). TauT activity was measured as the Na(+)-dependent uptake of (3)H-taurine into placental villous fragments. TauT expression in membrane-enriched placental samples was investigated by western blot. In vitro studies using placental villous explants examined whether leptin or IL-6, adipokines/cytokines that are elevated in maternal obesity, regulates TauT activity. RESULTS: Placental TauT activity was significantly lower in obese women (BMI⩾30) than women of ideal weight (P<0.03) and inversely related to maternal BMI (19-49 kg m(-)(2); P<0.05; n=61). There was no difference in TauT expression between placentas of ideal weight and obese class III (BMI⩾40) subjects. Long-term exposure (48 h) of placental villous explants to leptin or IL-6 did not affect TauT activity. CONCLUSIONS: Placental TauT activity at term is negatively related to maternal BMI. We propose that the reduction in placental TauT activity in maternal obesity could lower syncytiotrophoblast taurine concentration, compromise placental development and function, and reduce the driving force for taurine efflux to the fetus, thereby increasing the risk of poor pregnancy outcome.
Assuntos
Retardo do Crescimento Fetal/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Obesidade/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Complicações na Gravidez/metabolismo , Taurina/metabolismo , Adulto , Western Blotting , Índice de Massa Corporal , Proteínas de Transporte/biossíntese , Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Células Cultivadas , Vilosidades Coriônicas/metabolismo , Feminino , Retardo do Crescimento Fetal/etiologia , Humanos , Recém-Nascido , Obesidade/complicações , Placenta/fisiopatologia , Pré-Eclâmpsia/etiologia , Gravidez , NatimortoRESUMO
p32 is a conserved eukaryotic protein which is primarily expressed in the mitochondria and regulates cell proliferation, migration and metabolism in various tissues. In this study, we sought to examine the expression and function of p32 in the human placenta. p32 was highly expressed in the syncytiotrophoblast, the underlying cytotrophoblast (CTB), the vascular endothelium and by a proportion of cells in the villous stroma in first trimester and term placenta. p32 mRNA and protein expression was significantly higher in the first trimester of pregnancy than at term, and expression in the trophoblast was significantly reduced in placentas from women with fetal growth restriction (FGR). Small interfering RNA (siRNA)-mediated knockdown of p32 in term placental explants significantly reduced the number of Ki67-positive CTB, but did not alter CTB apoptosis or necrosis. p32 knockdown increased lactate production, reduced glucose extraction from culture medium and was associated with reduced MitoTracker dye accumulation in trophoblast mitochondria. p32 knockdown was also associated with a significant reduction in expression of the mitochondrial respiratory complexes I and IV. These data suggest that p32 expression is important for CTB proliferation, via a mechanism involving regulation of normal mitochondrial function. As p32 expression is reduced in FGR placentas, this may contribute to some of the observed placental pathology, such as reduced CTB proliferation and mitochondrial dysfunction.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas Mitocondriais/metabolismo , Trofoblastos/citologia , Trofoblastos/metabolismo , Proteínas de Transporte/genética , Proliferação de Células/genética , Proliferação de Células/fisiologia , Feminino , Retardo do Crescimento Fetal/genética , Retardo do Crescimento Fetal/metabolismo , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Proteínas Mitocondriais/genética , Placenta/metabolismo , Gravidez , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
The SBM mouse is a unique transgenic model of polycystic kidney disease (PKD) induced by the dysregulated expression of c-myc in renal tissue. In situ hybridization analysis demonstrated intense signal for the c-myc transgene overlying tubular cystic epithelium in SBM mice. Renal proliferation index in SBM kidneys was 10-fold increased over nontransgenic controls correlating with the presence of epithelial hyperplasia. The specificity of c-myc for the proliferative potential of epithelial cells was demonstrated by substitution of c-myc with the proto-oncogene c-fos or the transforming growth factor (TGF)-alpha within the same construct. No renal abnormalities were detected in 13 transgenic lines established, indicating that the PKD phenotype is dependent on functions specific to c-myc. We also investigated another well characterized function of c-myc, the regulation of apoptosis through pathways involving p53 and members of the bcl-2 family, which induce and inhibit apoptosis, respectively. The SBM kidney tissues, which overexpress c-myc, displayed a markedly elevated (10-100-fold) apoptotic index. However, no significant difference in bcl-2, bax, or p53 expression was observed in SBM kidney compared with controls. Direct proof that the heightened renal cellular apoptosis in PKD is not occurring through p53 was obtained by successive matings between SBM and p53(-/-) mice. All SBM offspring, irrespective of their p53 genotype, developed PKD with increased renal epithelial apoptotic index. In addition, overexpression of both bcl-2 and c-myc in double transgenic mice (SBB+/SBM+) also produced a similar PKD phenotype with a high apoptotic rate, showing that c-myc can bypass bcl-2 in vivo. Thus, the in vivo c-myc apoptotic pathway in SBM mice occurs through a p53- and bcl-2-independent mechanism. We conclude that the pathogenesis of PKD is c-myc specific and involves a critical imbalance between the opposing processes of cell proliferation and apoptosis.
Assuntos
Apoptose/genética , Rim Policístico Autossômico Dominante/patologia , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Proteínas Proto-Oncogênicas c-myc/fisiologia , Proteína Supressora de Tumor p53/fisiologia , Animais , Divisão Celular , Cruzamentos Genéticos , Modelos Animais de Doenças , Células Epiteliais/patologia , Expressão Gênica , Genes Sintéticos , Genes myc , Genes p53 , Hiperplasia , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Especificidade de Órgãos , Fenótipo , Rim Policístico Autossômico Dominante/genética , Proteínas Recombinantes de Fusão/fisiologia , TransgenesRESUMO
UNLABELLED: System A-mediated amino acid transport across the placenta is important for the supply of neutral amino acids needed for fetal growth. All three system A subtypes (SNAT1, 2, and 4) are expressed in human placental trophoblast suggesting there is an important biological role for each. Placental system A activity increases as pregnancy progresses, coinciding with increased fetal nutrient demands. We have previously shown SNAT4-mediated system A activity is higher in first trimester than at term, suggesting that SNAT1 and/or SNAT2 are responsible for the increased system A activity later in gestation. However, the relative contribution of each subtype to transporter activity in trophoblast at term has yet to be evaluated. The purpose of this study was to identify the predominant subtype of system A in cytotrophoblast cells isolated from term placenta, maintained in culture for 66h, by: (1) measuring mRNA expression of the three subtypes and determining the Michaelis-Menten constants for uptake of the system A-specific substrate, (14)C-MeAIB, (2) investigating the contribution of SNAT1 to total system A activity using siRNA. RESULTS: mRNA expression was highest for the SNAT1 subtype of system A. Kinetic analysis of (14)C-MeAIB uptake revealed two distinct transport systems; system 1: K(m)=0.38+/-0.12mM, V(max)=27.8+/-9.0pmol/mg protein/20min, which resembles that reported for SNAT1 and SNAT2 in other cell types, and system 2: K(m)=45.4+/-25.0mM, V(max)=1190+/-291pmol/mg protein/20min, which potentially represents SNAT4. Successful knockdown of SNAT1 mRNA using target-specific siRNA significantly reduced system A activity (median 75% knockdown, n=7). CONCLUSION: These data enhance our limited understanding of the relative importance of the system A subtypes for amino acid transport in human placental trophoblast by demonstrating that SNAT1 is a key contributor to system A activity at term.
Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Placenta/metabolismo , Sistema A de Transporte de Aminoácidos/genética , Células Cultivadas , Feminino , Técnicas de Silenciamento de Genes , Humanos , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Trofoblastos/metabolismoRESUMO
Placental system A activity is important for the supply of neutral amino acids needed for fetal growth. There are three system A isoforms: SNAT1, SNAT2 and SNAT4, but the contribution of each to system A-mediated transport is unknown. Here, we have used immunohistochemistry to demonstrate that all three isoforms are present in the syncytiotrophoblast suggesting each plays a role in amino acid transport across the placenta. We next tested the hypothesis that the SNAT4 isoform is functional in microvillous plasma membrane vesicles (MVM) from normal human placenta using a method which exploits the unique property of SNAT4 to transport both cationic amino acids as well as the system A-specific substrate MeAIB. The data show that SNAT4 contribution to system A-specific amino acid transport across MVM is higher in first trimester placenta compared to term (approx. 70% and 33%, respectively, P < 0.01). Further experiments performed under more physiological conditions using intact placental villous fragments suggest a contribution of SNAT4 to system A activity in first trimester placenta but minimal contribution at term. In agreement, Western blotting revealed that SNAT4 protein expression is higher in first trimester MVM compared to term (P < 0.05). This study provides the first evidence of SNAT4 activity in human placenta and demonstrates the contribution of SNAT4 to system A-mediated transport decreases between first trimester and term: our data lead us to speculate that at later stages of gestation SNAT1 and/or SNAT2 are more important for the supply of amino acids required for normal fetal growth.
Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Microvilosidades/metabolismo , Placenta/metabolismo , Sequência de Aminoácidos , Sistema A de Transporte de Aminoácidos/genética , Arginina/farmacologia , Feminino , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Microvilosidades/efeitos dos fármacos , Dados de Sequência Molecular , Placenta/efeitos dos fármacos , Gravidez , Primeiro Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , beta-Alanina/análogos & derivados , beta-Alanina/metabolismoRESUMO
The use of RNA interference (RNAi) to deplete individual proteins from cells or tissue has revolutionised our ability to characterise gene function. The placenta is an attractive target for studies in which the role of specific proteins can be compared with cell culture models and explanted villous tissue where physiological function can be maintained ex vivo. In this study, we compared a variety of commercially available reagents and approaches to define methods for efficient delivery of siRNA to placental cells. Protocols optimised using fluorescently-labelled siRNA were subsequently tested using siRNA sequences that target placental alkaline phosphatase (PLAP), chosen because of its high abundance in trophoblast. mRNA abundance was assayed using qRT-PCR, and the effect on protein was examined using immunolocalisation. We report that different protocols are required for BeWo choriocarcinoma cells (nucleofection), primary cytotrophoblast cells (lipid-based transfection) and villous tissue explants (nucleofection). The results provide guidelines for optimal siRNA-mediated knockdown in these three models of the human placenta.
Assuntos
Coriocarcinoma/genética , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Trofoblastos/metabolismo , Adulto , Fosfatase Alcalina , Linhagem Celular Tumoral , Coriocarcinoma/metabolismo , Coriocarcinoma/patologia , Feminino , Proteínas Ligadas por GPI , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Técnicas de Cultura de Órgãos , Gravidez , RNA Mensageiro/biossíntese , RNA Interferente Pequeno/metabolismo , Transfecção , Trofoblastos/citologia , Adulto JovemRESUMO
Every year in France, nearly 50 infants live in a prison nursery with their mother. According to French law, infants can live with their mother in the prison nursery until they reach 18 months of age. The international community is concerned about the lack of validated social, medical and legal data on these infants living in prison. This was a retrospective and descriptive study. Medical and paramedical files of the General Council of Île-et-Vilaine, France, were studied. Every infant born between 1998 and 2013 while their mother was in prison were included. Fifty-four files were collected. The average length of stay was 6.2 months (n=54). The type of the mother's prison sentence was property damage in 40 % of cases, personal injury in 51.1 % of cases and both in 8.9 % of cases (n=45). The length of the mother's imprisonment was on average 45 months, ranging from 3 to 216 months (n=34). After prison, 42.9 % of the infants were placed in foster care and 57.1 % resided with their family (n=42). This child-mother incarceration could be an opportunity for positive intergenerational paramedical, medical and social services. The lack of data and problems collecting data restrict our knowledge of these families. This should motivate a national follow-up for these children.
Assuntos
Berçários para Lactentes , Prisioneiros/estatística & dados numéricos , Prisões , Adolescente , Adulto , Feminino , França , Humanos , Lactente , Recém-Nascido , Masculino , Mães , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
Culture of explants derived from third trimester human placenta is used in a range of contexts as an experimental model that retains tissue architecture. This study aimed to explore the variability between, and within, individuals of secretion by explants of human chorionic gonadotrophin (hCG) and interleukin-6 (IL-6). Standard culture medium contained hydrocortisone, insulin, retinoic acid and serum. Under these conditions explants displayed significant differences in the time-course and extent of hCG secretion. Peak hCG secretion varied between 1.19 and 242 mIU/mg protein/h (coefficient of variation (CV) = 111%) and could occur between days 4 and 7 of culture. hCG secretion was more variable if explant protein was < 400 microg. Unadjusted day 7 hCG secretion showed marked variation: intra-placental CV = 15%, inter-placental CV = 86%. When day 7 hCG secretion was standardised by day 6 secretion, intra-placental CV was 6.9%, inter-placental CV was 4.0%. When this standardisation was applied, hCG secretion during day 7 of culture was not affected by removal of hydrocortisone, insulin or serum from the medium or by the addition of tumour necrosis factor-alpha (TNF-alpha). The secretion of IL-6 during day 7 of culture (standardised by taking natural logarithms) was increased markedly by the addition of TNF-alpha but unaltered by removing hydrocortisone, insulin or serum. Thus, we have shown that although variable, secretion by placental explants can be used to investigate how placental tissue adapts to different culture conditions. However, explants of the same protein content may have markedly different secretory properties.
Assuntos
Gonadotropina Coriônica/metabolismo , Interleucina-6/metabolismo , Placenta/efeitos dos fármacos , Placenta/metabolismo , Técnicas de Cultura de Tecidos/métodos , Meios de Cultura Livres de Soro/farmacologia , Feminino , Hormônios/farmacologia , Humanos , Gravidez , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Acute infection of fibroblastic cell lines by the Indiana strain of vesicular stomatitis virus (VSV) usually induces dramatic cytopathic effects and shutoff of cellular gene expression. We have compared a series of independent mutants with differences in shutoff induction and found that M was mutated either in the N-terminus (M(51)R) or C-terminus (V(221)F and S(226)R). Furthermore, only double mutants (M mutation and a ts mutation related or not to M) were able to persist on fibroblast cell lines at 39 degrees C. A more detailed investigation of the infection was performed for the mutants T1026, TP3 and G31, differing in their host shutoff effects related to M protein. Viral activity in persistently infected mouse L-929 and monkey Vero cell lines was followed by viral proteins detection, RNA synthesis throughout infection and finally detection of infectious particles. All three mutants cause extensive CPE followed by emergence of persistently infected cells on Vero cells. The same thing is seen on L-929 cells except for T1026 which causes little CPE. Taken together, the results form a basis of further studies to clarify how various viral and cellular factors interact in the establishment of a persistent infection by VSV mutants.
Assuntos
Regulação para Baixo , Fibroblastos/metabolismo , Fibroblastos/virologia , Vírus da Estomatite Vesicular Indiana/fisiologia , Proteínas da Matriz Viral/metabolismo , Replicação Viral , Animais , Tamanho Celular , Sobrevivência Celular , Chlorocebus aethiops , Fibroblastos/citologia , Células L , Camundongos , Mutação , Biossíntese de Proteínas , Proteínas/análise , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , RNA Viral/análise , Células Vero , Vírus da Estomatite Vesicular Indiana/genética , Vírus da Estomatite Vesicular Indiana/patogenicidade , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/genética , Proteínas Virais/análiseRESUMO
The mouse apolipoprotein D gene was isolated from a brain cDNA library. The nucleotide sequence contains a unique reading frame coding for a protein sharing 79.5% homology with human apoD, 86.2% homology with rabbit apoD and 92.6% homology with rat apoD. The four sequences have two potential asparagine-linked glycosylation sites at residues 45 and 78, and possess the two consensus sequences of the lipocalin family which coincide with the most conserved regions in the four species studied. The distribution of apoD mRNA among mouse organs was determined by Northern blot and quantitative dot blot analysis. The highest levels of mRNA were found in the central nervous system (CNS), namely in the spinal cord, the cerebellum and the brain. Very low concentrations were detected in all the other organs tested. In some organs (spleen, kidney, intestines, heart), a second messenger of lower molecular weight was detected. Gene expression was also measured in rat tissues. As in the mouse, rat CNS was found to be by far the highest expressor of apoD mRNA, in contrast to the rabbit and human. Levels of expression in most mouse and rat organs appeared to be much lower than in the same organs of the rabbit and human. Since apoD is expressed at sites of nerve regeneration as well as apoE, our results raise the question of whether or not the two proteins play a coordinated role in the CNS.
Assuntos
Apolipoproteínas/metabolismo , Encéfalo/metabolismo , RNA Mensageiro/metabolismo , Animais , Apolipoproteínas/genética , Apolipoproteínas D , Sequência de Bases , Northern Blotting , DNA Complementar , Expressão Gênica , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Distribuição TecidualRESUMO
The outer epithelial cell layer of human placenta, the syncytiotrophoblast, is a specialised terminally differentiated multinucleate tissue. It is generated and renewed from underlying cytotrophoblast cells that undergo proliferation, differentiation and fusion with syncytiotrophoblast. Acquisition of fresh cellular components is thought to be balanced by apoptosis and shedding of aged nuclei. This process of trophoblast cell turnover maintains a functional syncytiotrophoblast, capable of sufficient nutrient transfer from mother to foetus. Foetal growth restriction (FGR) is a pregnancy complication associated with aberrant trophoblast turnover and reduced activity of certain amino acid transporters, including the taurine transporter (TauT). Taurine is the most abundant amino acid in human placenta implying an important physiological role within this tissue. Unlike other amino acids, taurine is not incorporated into proteins and in non-placental cell types represents an important osmolyte involved in cell volume regulation, and is also cytoprotective. Here, we investigated the role of taurine in trophoblast turnover using RNA interference to deplete primary human trophoblast cells of TauT and reduce intracellular taurine content. Trophoblast differentiation was compromised in TauT-deficient cells, and susceptibility of these cells to an inflammatory cytokine that is elevated in FGR was increased, evidenced by elevated levels of apoptosis. These data suggest an important role for taurine in trophoblast turnover and cytoprotection.
Assuntos
Retardo do Crescimento Fetal/genética , Glicoproteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Taurina/metabolismo , Trofoblastos/metabolismo , Apoptose , Transporte Biológico , Diferenciação Celular , Tamanho Celular , Sobrevivência Celular/genética , Citoproteção , Feminino , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/patologia , Expressão Gênica , Técnicas de Silenciamento de Genes , Meia-Vida , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/deficiência , Proteínas de Membrana Transportadoras/deficiência , Gravidez , RNA Interferente Pequeno/genética , Taurina/farmacologia , Trofoblastos/patologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2011 there were twelve themed workshops, three of which are summarized in this report. These workshops related to vascular systems and circulation in the mother, placenta and fetus, and were divided in to 1) angiogenic signaling and regulation of fetal endothelial function; 2) placental and fetal circulation and growth; 3) spiral artery remodeling.
Assuntos
Nível de Saúde , Placenta/fisiologia , Animais , Pesquisa Biomédica/tendências , Endométrio/irrigação sanguínea , Endotélio Vascular/embriologia , Endotélio Vascular/fisiologia , Feminino , Desenvolvimento Fetal , Humanos , Masculino , Neovascularização Fisiológica , Obstetrícia/tendências , Circulação Placentária , Placentação , Gravidez , Transdução de SinaisRESUMO
Transfection using cationic lipid reagents such as DharmaFECT2 is an efficient tool for introducing siRNA into primary human cytotrophoblast cells. However, we now report a limitation to the use of this method as the concentration of DharamFECT2 needed for effective siRNA delivery causes ligand-independent activation of the insulin/insulin-like growth factor (IGF) receptor and consequently, functional resistance to cytotrophoblast stimulation by these two hormones. We therefore advise researchers against the use of this method of transfection when investigating the mechanisms by which insulin/IGF, and potentially other hormones that exert their effects through kinase signalling molecules, influence cytotrophoblast cell function.
Assuntos
RNA Interferente Pequeno/administração & dosagem , Transfecção/métodos , Trofoblastos/fisiologia , Feminino , Humanos , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Gravidez , Receptor IGF Tipo 1/efeitos dos fármacos , Trofoblastos/metabolismoRESUMO
Plasma corticotrophin-releasing factor (CRF) and urocortin are elevated in preterm labour and/or fetal growth restriction (FGR). FGR is associated with reduced placental system A amino acid transporter activity and in vitro data suggest altered endocrine status could be responsible. Here we test the hypothesis that CRF and urocortin inhibit placental system A activity. Chronic (48h) exposure of term placental villous explants to these hormones (10(-7)M) significantly reduced system A activity (Na(+)-dependent (14)C-methylaminoisobutyric acid uptake), whereas 1h exposure had no effect. We propose elevated CRF and urocortin contribute to FGR through negative regulation of placental system A activity.
Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Vilosidades Coriônicas/efeitos dos fármacos , Hormônio Liberador da Corticotropina/farmacologia , Urocortinas/farmacologia , Biópsia , Células Cultivadas , Gonadotropina Coriônica/farmacologia , Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/patologia , Regulação para Baixo , Feminino , Idade Gestacional , Humanos , Ouabaína/farmacologia , Gravidez , Nascimento a Termo/metabolismo , Nascimento a Termo/fisiologia , Fatores de TempoAssuntos
Anestésicos , Animais Domésticos , Patos , Animais , Carbamatos , Combinação de Medicamentos , Injeções Intravenosas , Metoexital , Pentobarbital , PropilenoglicóisRESUMO
The system A amino acid transporter is encoded by three members of the Slc38 gene family, giving rise to three subtypes: Na+-coupled neutral amino acid transporter (SNAT)1, SNAT2, and SNAT4. SNAT2 is expressed ubiquitously in mammalian tissues; SNAT1 is predominantly expressed in heart, brain, and placenta; and SNAT4 is reported to be expressed solely by the liver. In the placenta, system A has an essential role in the supply of neutral amino acids needed for fetal growth. In the present study, we examined expression and localization of SNAT1, SNAT2, and SNAT4 in human placenta during gestation. Real-time quantitative PCR was used to examine steady-state levels of system A subtype mRNA in early (6-10 wk) and late (10-13 wk) first-trimester and full-term (38-40 wk) placentas. We detected mRNA for all three isoforms from early gestation onward. There were no differences in SNAT1 and SNAT2 mRNA expression with gestation. However, SNAT4 mRNA expression was significantly higher early in the first trimester compared with the full-term placenta (P < 0.01). We next investigated SNAT4 protein expression in human placenta. In contrast to the observation for gene expression, Western blot analysis revealed that SNAT4 protein expression was significantly higher at term compared with the first trimester (P < 0.05). Immunohistochemistry and Western blot analysis showed that SNAT4 is localized to the microvillous and basal plasma membranes of the syncytiotrophoblast, suggesting a role for this isoform of system A in amino acid transport across the placenta. This study therefore provides the first evidence of SNAT4 mRNA and protein expression in the human placenta, both at the first trimester and at full term.
Assuntos
Sistema A de Transporte de Aminoácidos/genética , Placenta/fisiologia , Sistema A de Transporte de Aminoácidos/metabolismo , Feminino , Expressão Gênica/fisiologia , Humanos , Especificidade de Órgãos , Gravidez , Primeiro Trimestre da Gravidez , Terceiro Trimestre da Gravidez , RNA Mensageiro/análiseRESUMO
BACKGROUND: The evaluation of community services for preschool children is hampered by the lack of valid and routinely available outcome measures. This study examines the use of data collected by teachers in response to educational legislation to determine whether a routine measure of attainments in primary school is sensitive to factors known to affect mental development. METHOD: A community child health dataset for the cohort of children born in Sheffield in 1990-1991 was matched with a dataset provided by schools in 1995-1996. The educational data consisted of the Infant Index scores which measure education attainments in reception class pupils. RESULTS: We matched 4487 children from both datasets, which represented 75 per cent of all children born in the 1990-1991 cohort. Factors which predicted a poor Infant Index included male gender (odds ratio (OR) = 2.1, 95 per cent confidence interval (CI)= 1.8-2.6), low birthweight (OR = 1.4, 95 per cent CI = 1.1-1.9) and lack of breast feeding either by intention to feed (OR = 1.3, 95 per cent CI = 1.1-1.7) or actual feeding practice at one month (OR = 1.5, 95 per cent CI = 1.1-2.0). Other factors associated with a poor outcome for the child were postnatal depression, number of pregnancies, ethnicity, pre-school educational experiences and poor housing. CONCLUSIONS: Although the results are interesting in themselves, the main significance of our project is in establishing a link between routinely collected health data and routine education data. This could facilitate research in the future thus leading to a considerable saving in the cost of long-term intervention studies.