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BACKGROUND: Person-Centered Care (PCC) is a promising approach towards improved quality of care and cost containment within health systems. It has been evaluated in Sweden and England. This feasibility study examines initial PCC implementation in a rehabilitation hospital for children in Poland. METHODS: The WE-CARE Roadmap of enablers was used to guide implementation of PCC for patients with moderate scoliosis. A multi-disciplinary team of professionals were trained in the PCC approach and the hospital Information Technology (IT) system was modified to enhance PCC data capture. Semi-structured interviews were conducted with the nine health care professionals involved in the pilot study and three patients/parents receiving care. Transcribed data were analyzed via content analysis. RESULTS: 51 patients and their families were treated via a PCC approach. High proportions of new PCC data fields were completed by the professionals. The professionals were able to implement the three core PCC routines and perceived benefits using the PCC approach. Patients and their families also perceived improved quality care. The WE-CARE framework enablers facilitated PCC implementation in this setting. CONCLUSIONS: This feasibility pilot study indicates that the Gothenburg PCC approach can be successfully transferred to a rehabilitation hospital in Poland with favorable perceptions of implementation by both professionals and patients/their families.
Assuntos
Assistência Centrada no Paciente , Criança , Inglaterra , Estudos de Viabilidade , Humanos , Projetos Piloto , Polônia , SuéciaRESUMO
BACKGROUND: Increasing healthcare costs need to be contained in order to maintain equality of access to care for all EU citizens. A cross-disciplinary consortium of experts was supported by the EU FP7 research programme, to produce a roadmap on cost containment, while maintaining or improving the quality of healthcare. The roadmap comprises two drivers: person-centred care and health promotion; five critical enablers also need to be addressed: information technology, quality measures, infrastructure, incentive systems, and contracting strategies. METHOD: In order to develop and test the roadmap, a COST Action project was initiated: COST-CARES, with 28 participating countries. This paper provides an overview of evidence about the effects of each of the identified enablers. Intersections between the drivers and the enablers are identified as critical for the success of future cost containment, in tandem with maintained or improved quality in healthcare. This will require further exploration through testing. CONCLUSION: Cost containment of future healthcare, with maintained or improved quality, needs to be addressed through a concerted approach of testing key factors. We propose a framework for test lab design based on these drivers and enablers in different European countries.
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Point mutations and deletions of mitochondrial DNA (mtDNA) accumulate in a variety of tissues during ageing in humans, monkeys and rodents. These mutations are unevenly distributed and can accumulate clonally in certain cells, causing a mosaic pattern of respiratory chain deficiency in tissues such as heart, skeletal muscle and brain. In terms of the ageing process, their possible causative effects have been intensely debated because of their low abundance and purely correlative connection with ageing. We have now addressed this question experimentally by creating homozygous knock-in mice that express a proof-reading-deficient version of PolgA, the nucleus-encoded catalytic subunit of mtDNA polymerase. Here we show that the knock-in mice develop an mtDNA mutator phenotype with a threefold to fivefold increase in the levels of point mutations, as well as increased amounts of deleted mtDNA. This increase in somatic mtDNA mutations is associated with reduced lifespan and premature onset of ageing-related phenotypes such as weight loss, reduced subcutaneous fat, alopecia (hair loss), kyphosis (curvature of the spine), osteoporosis, anaemia, reduced fertility and heart enlargement. Our results thus provide a causative link between mtDNA mutations and ageing phenotypes in mammals.
Assuntos
Senilidade Prematura/enzimologia , Senilidade Prematura/genética , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Mitocôndrias/enzimologia , Mutagênese/genética , Mutação/genética , Tecido Adiposo , Senilidade Prematura/complicações , Senilidade Prematura/patologia , Alopecia/complicações , Alopecia/enzimologia , Alopecia/genética , Animais , Composição Corporal , Peso Corporal , Densidade Óssea/genética , Análise Mutacional de DNA , DNA Polimerase gama , DNA Mitocondrial/genética , Homozigoto , Cifose/complicações , Cifose/enzimologia , Cifose/genética , Camundongos , Fenótipo , Transgenes/genéticaRESUMO
The hypothalamic peptide melanin-concentrating hormone (MCH) plays important roles in energy homeostasis. Animals overexpressing MCH develop hyperphagia, obesity, and insulin resistance. In this study, mice lacking both the MCH receptor-1 (MCHr1 knockout) and leptin (ob/ob) double-null mice (MCHr1 knockout ob/ob) were generated to investigate whether the obesity and/or the insulin resistance linked to the obese phenotype of ob/ob mice was attenuated by ablation of the MCHr1 gene. In MCHr1 knockout ob/ob mice an oral glucose load resulted in a lower blood glucose response and markedly lower insulin levels compared with the ob/ob mice despite no differences in body weight, food intake, or energy expenditure. In addition, MCHr1 knockout ob/ob mice had higher locomotor activity and lean body mass, lower body fat mass, and altered body temperature regulation compared with ob/ob mice. In conclusion, MCHr1 is important for insulin sensitivity and/or secretion via a mechanism not dependent on decreased body weight.
Assuntos
Peso Corporal , Resistência à Insulina , Leptina/deficiência , Obesidade/metabolismo , Receptores de Somatostatina/fisiologia , Animais , Composição Corporal , Regulação da Temperatura Corporal , Hormônio Liberador da Corticotropina/análise , Ingestão de Alimentos , Glucose/metabolismo , Camundongos , Camundongos Obesos , Atividade Motora , RNA Mensageiro/análise , Receptores para Leptina , Receptores de Somatostatina/deficiência , Estearoil-CoA Dessaturase/genéticaRESUMO
Renal cell carcinoma (RCC), arising from the proximal tubule in the kidney, accounts for approximately 85% of kidney cancers and causes over 140,000 annual deaths worldwide. In the last decade, several new therapies have been identified for treatment of metastatic RCC. Although these therapies increase survival time compared to standard care, none of them has curative properties. The nephrotoxin orellanine specifically targets proximal tubular epithelial cells, leaving other organs unaffected. We therefore hypothesized that the selective toxicity of orellanine extends to clear cell RCC (ccRCC) cells since they emanate from proximal tubular cells. Orellanine would thus target both primary and metastatic ccRCC in vitro and in vivo. We found that orellanine induces dose-dependent cell death in proximal tubular cells and in all ccRCC cells tested, both primary and cell lines, with no toxicity detected in control cells. The toxic action of orellanine involve decreased protein synthesis, disrupted cell metabolism and induction of apoptosis. In nude rats carrying human ccRCC xenografts, brief orellanine treatment eliminated more than 90% of viable tumor mass compared to control rats. This identifies orellanine as a potential treatment concept for ccRCC patients on dialysis, due to its unique selective toxicity towards ccRCC.
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It is well known that peripherally administered growth hormone (GH) results in decreased body fat mass. However, GH-deficient patients increase their food intake when substituted with GH, suggesting that GH also has an appetite stimulating effect. Transgenic mice with an overexpression of bovine GH in the central nervous system (CNS) were created to investigate the role of GH in CNS. This study shows that overexpression of GH in the CNS differentiates the effect of GH on body fat mass from that on appetite. The transgenic mice were not GH-deficient but were obese and showed increased food intake as well as increased hypothalamic expression of agouti-related protein and neuropeptide Y. GH also had an acute effect on food intake following intracerebroventricular injection of C57BL/6 mice. The transgenic mice were severely hyperinsulinemic and showed a marked hyperplasia of the islets of Langerhans. In addition, the transgenic mice displayed alterations in serum lipid and lipoprotein levels and hepatic gene expression. In conclusion, GH overexpression in the CNS results in hyperphagia-induced obesity indicating a dual effect of GH with a central stimulation of appetite and a peripheral lipolytic effect.
Assuntos
Hormônio do Crescimento/genética , Hiperlipidemias/genética , Hiperfagia/genética , Resistência à Insulina/genética , Obesidade/etiologia , Tecido Adiposo/anatomia & histologia , Animais , Sequência de Bases , Glicemia/metabolismo , Peso Corporal , Calorimetria Indireta , Bovinos , Sondas de DNA , Ingestão de Energia/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Genoma , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/farmacologia , Hormônio do Crescimento/fisiologia , Hiperinsulinismo/induzido quimicamente , Hiperfagia/sangue , Hiperfagia/fisiopatologia , Hipotálamo/fisiologia , Injeções Intraventriculares , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/sangueRESUMO
It is known that bovine GH (bGH) transgenic mice have increased body mass, insulin resistance, and altered lipoprotein metabolism when fed a normal diet (ND). In this study, the effects of 8 wk of high-fat diet (HFD) were investigated in 6-month-old male bGH mice. Although littermate controls had unchanged energy intake, energy intake was higher in the bGH mice on a HFD than on a low-fat diet. Nevertheless, the bGH mice were resistant to diet-induced weight gain, and only in the bGH mice did the HFD result in increased energy expenditure. Glucose oxidation was higher in the bGH mice compared with littermate controls on both a HFD and ND. In addition, the bGH mice had 0.5 C higher body temperature throughout the day and increased hepatic uncoupling protein 2 expression; changes that were unaffected by the HFD. On a HFD, the effect of bGH overexpression on serum triglycerides and apolipoprotein B was opposite to that on a ND, resulting in higher serum concentrations of triglycerides and apolipoprotein B compared with littermate controls. Increased serum triglycerides were explained by decreased triglyceride clearance. The HFD led to diabetes only in the bGH mice. In conclusion, bGH transgenic mice were resistant to diet-induced obesity despite hyperphagia, possibly due to increased energy expenditure. On a HFD, bGH mice became dyslipidemic and diabetic and thereby more accurately reflect the metabolic situation in acromegalic patients.
Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Hormônio do Crescimento/genética , Hiperlipidemias/fisiopatologia , Hiperfagia/fisiopatologia , Obesidade/fisiopatologia , Acromegalia/metabolismo , Acromegalia/fisiopatologia , Animais , Composição Corporal , Temperatura Corporal , Proteínas de Transporte/genética , Bovinos , Diabetes Mellitus Experimental/metabolismo , Gorduras na Dieta/farmacologia , Ingestão de Alimentos , Metabolismo Energético/fisiologia , Teste de Tolerância a Glucose , Hiperlipidemias/metabolismo , Hiperfagia/metabolismo , Canais Iônicos , Lipídeos/sangue , Lipoproteínas/sangue , Proteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Transgênicos , Proteínas Mitocondriais/genética , Obesidade/metabolismo , Consumo de Oxigênio/fisiologia , Proteína Desacopladora 1 , Proteína Desacopladora 2RESUMO
Mice deficient for all known thyroid hormone receptors, TRalpha1-/-beta-/- mice, display a clear skeletal phenotype characterized by growth retardation, delayed maturation of long bones and decreased trabecular and total bone mineral density (BMD; -14.6 +/- 2.8%, -14.4 +/- 1.5%). The aim of the present study was to investigate the molecular mechanisms behind the skeletal phenotype in TRalpha1-/-beta-/- mice. Global gene expression analysis was performed on total vertebrae from wild-type (WT) and TRalpha1-/-beta-/- mice using DNA microarray and the results were verified by real-time PCR. The mRNA levels of six genes (AdipoQ, Adipsin, Fat-Specific Protein 27 (FSP 27), lipoprotein lipase (LPL), retinol-binding protein (RBP) and phosphoenolpyruvate carboxykinase (PEPCK)) expressed by mature adipocytes were increased in TRalpha1-/-beta-/- compared with WT mice. An increased amount of fat (225% over WT) due to an increased number but unchanged mean size of adipocytes in the bone marrow of TRalpha1-/-beta-/- mice was revealed. Interestingly, the mRNA levels of the key regulator of osteoclastogenesis, receptor activator of NF-varkappab ligand (RANKL), were dramatically decreased in TRalpha1-/-beta-/- mice. In conclusion, TRalpha1-/-beta-/- mice demonstrated increased expression of adipocyte specific genes and an increased amount of bone marrow fat. Thus, these mice have increased adipogenesis in bone marrow associated with decreased trabecular bone mineral density (BMD). One may speculate that these effects either could be caused by an imbalance in the differentiation of the osteoblast and the adipocyte lineages at the expense of osteoblastogenesis, or by independent effects on the regulation of both osteoblastogenesis and adipogenesis.
Assuntos
Adipócitos/citologia , Composição Corporal , Densidade Óssea , Medula Óssea/metabolismo , Receptores dos Hormônios Tireóideos/fisiologia , Adipócitos/metabolismo , Adiponectina , Animais , Sequência de Bases , Fator D do Complemento , Primers do DNA , Peptídeos e Proteínas de Sinalização Intercelular/genética , Lipase Lipoproteica/genética , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , RNA Mensageiro/genética , Receptores dos Hormônios Tireóideos/genética , Proteínas de Ligação ao Retinol/genética , Serina Endopeptidases/genéticaRESUMO
Insulin-like growth factor (IGF) I is an important regulator of both skeletal growth and adult bone metabolism. To better understand the relative importance of systemic IGF-I versus locally expressed IGF-I we have developed a transgenic mouse model with inducible specific IGF-I gene inactivation in the liver (LI-IGF-I-/-). These mice are growing normally up to 12 weeks of age but have a disturbed carbohydrate and lipid metabolism. In this study, the long-term effects of liver-specific IGF-I inactivation on skeletal growth and adult bone metabolism were investigated. The adult (week 8-55) axial skeletal growth was decreased by 24% in the LI-IGF-I-/- mice whereas no major reduction of the adult appendicular skeletal growth was seen. The cortical cross-sectional bone area, as measured in the middiaphyseal region of the long bones, was decreased in old LI-IGF-I-/- mice. This reduction in the amount of cortical bone was caused mainly by decreased periosteal circumference and was associated with a weaker bone determined by a decrease in ultimate load. In contrast, the amount of trabecular bone was not decreased in the LI-IGF-I-/- mice. DNA microarray analysis of 30-week-old LI-IGF-I-/- and control mice indicated that only four genes were regulated in bone whereas approximately 40 genes were regulated in the liver, supporting the hypothesis that liver-derived IGF-I is of minor importance for adult bone metabolism. In summary, liver-derived IGF-I exerts a small but significant effect on cortical periosteal bone growth and on adult axial skeletal growth while it is not required for the maintenance of the trabecular bone in adult mice.
Assuntos
Osso e Ossos/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Fígado/fisiologia , Absorciometria de Fóton , Animais , Biomarcadores/sangue , Densidade Óssea , Desenvolvimento Ósseo/genética , Reabsorção Óssea , Regulação da Expressão Gênica no Desenvolvimento , Mecânica , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Especificidade de ÓrgãosRESUMO
Pharmaceutical companies are faced with the challenge that only approximately 10% of compounds tested in costly clinical trials eventually become a new drug. Investment in early discovery research can decrease this attrition in late-stage R&D and focus resources on the best targets. Transgenic technology influences decision-making in target identification, target validation, and can also provide better models for human diseases, as well as models designed to alert researchers early about potential issues with drug metabolism and toxicity. Here we review how transgenic technology can reduce the late-stage attrition by increasing the quality of both the target and the compound.
Assuntos
Animais Geneticamente Modificados/genética , Camundongos Transgênicos/genética , Farmacologia/métodos , Animais , Modelos Animais de Doenças , Indústria Farmacêutica , Humanos , Camundongos , Reprodutibilidade dos TestesRESUMO
Identification of tissue-specific mechanisms involved in the pathophysiology of inflammatory skin diseases could offer new possibilities to develop effective therapies with fewer systemic effects. The serine protease stratum corneum chymotryptic enzyme is preferentially expressed in cornifying epithelia. We have previously reported on increased expression of the stratum corneum chymotryptic enzyme in psoriasis. Here is reported an increased epidermal expression of stratum corneum chymotryptic enzyme also found in chronic lesions of atopic dermatitis. Transgenic mice expressing human stratum corneum chymotryptic enzyme in suprabasal epidermal keratinocytes were found to develop pathologic skin changes with increased epidermal thickness, hyperkeratosis, dermal inflammation, and severe pruritus. The results suggest that stratum corneum chymotryptic enzyme may be involved in the pathogenesis of inflammatory skin diseases, and that stratum corneum chymotryptic enzyme and related enzymes should be evaluated as potential targets for new therapies.
Assuntos
Dermatite/etiologia , Dermatite/fisiopatologia , Epiderme/enzimologia , Prurido , Serina Endopeptidases/metabolismo , Sequência de Aminoácidos/genética , Animais , Doença Crônica , Dermatite/patologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Humanos , Calicreínas , Camundongos , Camundongos Transgênicos/genética , Fenótipo , Serina Endopeptidases/genética , Pele/patologiaRESUMO
Prolactin (PRL) is one of several polypeptide factors known to exert trophic effects on the prostate. We have previously reported a dramatic prostate enlargement with concurrent chronic hyperprolactinemia and elevated serum androgen levels in a PRL transgenic mouse (Mt-PRL) with ubiquitous expression of the transgene. To address the role of local PRL action in the prostate, a new transgenic mouse model (Pb-PRL) was generated using the prostate-specific rat probasin (Pb) minimal promoter to drive expression of the rat PRL gene. Pb-PRL transgenic males developed a significant enlargement of both the dorsolateral and ventral prostate lobes evident from 10 wk of age and increasing with age. Expression of the transgene was restricted to the prostate and detected from 4 wk of age. Low levels of transgenic rat PRL were detectable in the serum of adult Pb-PRL animals. Serum androgen levels were normal. The Pb-PRL prostate displayed significant stromal hyperplasia, ductal dilation, and focal areas of epithelial dysplasia. Quantitative analysis of prostatic tissue cellularity demonstrated a marked increase in the stromal to epithelial ratio in all lobes of Mt-PRL and Pb-PRL transgenic prostates compared with controls. Microdissections demonstrated an increased ductal morphogenesis in dorsolateral and ventral prostate lobes of Mt-PRL prostate vs. Pb-PRL and controls. In conclusion, this study indicates the ability of PRL to promote, directly or indirectly, ductal morphogenesis in the developing prostate and further to induce abnormal growth primarily of the stroma in the adult gland in a setting of normal androgen levels.
Assuntos
Prolactina/genética , Próstata/fisiologia , Hiperplasia Prostática/fisiopatologia , Animais , Contagem de Células , Células Epiteliais/patologia , Expressão Gênica/fisiologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Prolactina/sangue , Próstata/química , Próstata/patologia , Hiperplasia Prostática/patologia , Receptores Androgênicos/análise , Receptores de Estrogênio/análise , Células Estromais/química , Células Estromais/patologia , Testosterona/sangue , Transgenes/genéticaRESUMO
The probasin (Pb)-PRL transgenic mice that overexpress the rat PRL gene specifically in the prostate develop a dramatic enlargement of the prostate gland. The objective of this study was to characterize the molecular mechanisms involved in the prostate hyperplasia seen in the Pb-PRL transgenic mice. cDNA microarray analysis was used to identify differentially expressed transcripts in the hyperplastic prostates of 6-month-old transgenic mice compared with age-matched controls. We report the identification of 266 genes (175 up-regulated and 91 down-regulated) that were differentially expressed in the enlarged transgenic prostates compared with controls. Subsequential real-time RT-PCR was used to verify a set of differentially regulated transcripts. The hyperplastic prostates of Pb-PRL transgenic mice demonstrate a molecular pattern supporting the importance of reduced degree of apoptosis for the development of the phenotype. Immunohistochemical analysis of apoptotic activity using two different markers of apoptosis (single-stranded DNA and activated caspase-3) were performed, and the results showed diminished apoptosis activity in the prostate of Pb-PRL transgenic mice compared with control prostates. The increased stromal/epithelial ratio of the Pb-PRL transgenic prostate together with up-regulation of a significant fraction of genes involved in tissue remodeling activity, including the synthesis and degradation of the extracellular matrix and changes in protease activity, suggest that activation of the stroma is involved in the development of prostate hyperplasia. Overall, the differentially expressed transcripts identified in this study show many molecular similarities between the prostate hyperplasia of PRL-transgenic mice and human prostate pathology, including both benign prostatic hyperplasia and prostate cancer.
Assuntos
Expressão Gênica , Prolactina/genética , Próstata/metabolismo , Hiperplasia Prostática/metabolismo , Proteína de Ligação a Androgênios/genética , Animais , Apoptose , Sistemas Computacionais , Regulação para Baixo , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Hiperplasia Prostática/genética , Hiperplasia Prostática/fisiopatologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para CimaRESUMO
We have previously demonstrated that GH is subject to rapid receptor-dependent nuclear translocation. Here, we examine the importance of ligand activation of the GH-receptor (GHR)-associated Janus kinase (JAK) 2 and receptor dimerization for hormone internalization and nuclear translocation by use of cells stably transfected with cDNA for the GHR. Staurosporine and herbimycin A treatment of cells did not affect the ability of GH to internalize but resulted in increased nuclear accumulation of hormone. Similarly, receptor mutations, which prevent the association and activation of JAK2, did not affect the ability of the hormone to internalize or translocate to the nucleus but resulted in increased nuclear accumulation of GH. These results were observed both by nuclear isolation and confocal laser scanning microscopy. Staurosporine treatment of cells in which human GH (hGH) was targeted to the cytoplasm (removal of secretion sequence) or to the nucleus (addition of the nuclear localization sequence of SV40 large T antigen) resulted in preferential accumulation of hGH in the nucleus. We further investigated the requirement of receptor dimerization for GH nuclear translocation using the non-receptor-dimerizing hGH antagonist, hGH-G120R, conjugated to fluorescein isothiocyanate. Confocal laser scanning microscopy demonstrated efficient internalization of both hGH and hGH-G120R but lack of nuclear translocation of hGH-G120R. Thus, we conclude that activation of JAK2 kinase and the subsequent tyrosine phosphorylation is not required for nuclear translocation of GH but is pivotal for the removal of the hormone from the nucleus, and that GH translocates into the nucleus in a GHR dimerized-dependent fashion.
Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Hormônio do Crescimento/metabolismo , Proteínas Proto-Oncogênicas , Receptores da Somatotropina/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Núcleo Celular/metabolismo , Cricetinae , Citoplasma/metabolismo , DNA Complementar , Dimerização , Inibidores Enzimáticos/farmacologia , Ensaio de Imunoadsorção Enzimática , Deleção de Genes , Janus Quinase 2 , Ligantes , Microscopia Confocal , Dados de Sequência Molecular , Mutagênese , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Ratos , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores da Somatotropina/química , Receptores da Somatotropina/genética , Estaurosporina/farmacologia , TransfecçãoRESUMO
Hyperprolactinemia results in prostatic hypertrophy and hyperplasia, but it is not known whether prolactin plays an essential role in these processes in the prostate. To address this question, we investigated prostate development, gene expression, and simian virus 40 (SV40)T-induced prostate carcinogenesis in prolactin receptor knockout mice. These animals showed a small increase in dorsolateral and ventral prostate weight but no change in the weight of the anterior prostate. The dorsal but not ventral or lateral lobes showed a 12% loss of epithelial cells; all other morphological parameters were normal. The area of SV40T-induced prostate intraepithelial neoplasia was reduced by 28% in the ventral lobe but not the dorsal lobe, and no tumors were seen in 20 prolactin receptor knockout animals, compared with 1 of 11 detected in wild-type and 4 of 21 found in heterozygous animals. Oligonucleotide microarrays were used to identify essential transcriptional roles of prolactin and revealed a small set of genes with decreased expression involved in sperm/oocyte interaction and copulatory plug formation. Infertility or reduced fertility was apparent in these animals. These findings establish essential though subtle roles for prolactin in the regulation of prostate morphology, gene expression, SV40T-induced neoplasia, and reproductive function.
Assuntos
Próstata/crescimento & desenvolvimento , Próstata/patologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/fisiopatologia , Receptores da Prolactina/genética , Androgênios/fisiologia , Animais , Antígenos Transformantes de Poliomavirus/genética , Complemento C3/genética , Feminino , Expressão Gênica , Hiperprolactinemia/patologia , Hiperprolactinemia/fisiopatologia , Infertilidade Masculina/patologia , Infertilidade Masculina/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , Orquiectomia , Gravidez , Regiões Promotoras Genéticas , RNA Mensageiro/análiseRESUMO
Insulin resistance is a key marker of both obesity and GH excess. The purpose of the study was to assess the role of GH on p53-mediated insulin resistance of male mice with obesity due to a high-fat diet. C57BL/6J × CBA male mice fed on a high-fat diet (Obe) were studied; male mice fed a normal diet (Lean) or transgenic mice for bovine GH under the same genetic background (Acro) served as controls. The convergence of p53 and GH pathways was evaluated by Western blot. Obe mice had insulin resistance, which was sustained by a selective increased expression of p53 in adipose tissue. Normal insulin sensitivity was restored, and adipose p53 expression normalized when the GH pathway was blocked. Only the adipose p53 expression was sensitive to the GH blockage, which occurred through the p38 pathway. Adipose tissue of Obe mice had a coordinate overexpression of suppressors of cytokine signal 1-3 and signal transducers and activators of transcription-1, -3, and -5b, not different from that of Acro mice, suggesting an increased sensitivity of adipose tissue to GH. On the contrary, Lean mice were unaffected by changes of GH action. GH seems to be necessary for the increased adipose p53 expression and for insulin resistance of obese mice.
Assuntos
Hormônio do Crescimento/metabolismo , Obesidade/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acromegalia , Tecido Adiposo/metabolismo , Animais , Hormônio do Crescimento/genética , Resistência à Insulina , Masculino , Camundongos , Camundongos Transgênicos , Proteína Supressora de Tumor p53/genéticaRESUMO
GH therapy improves hippocampal functions mainly via circulating IGF1. However, the roles of local GH and IGF1 expression are not well understood. We investigated whether transgenic (TG) overexpression in the adult brain of bovine GH (bGH) under the control of the glial fibrillary acidic protein (GFAP) promoter affected cellular proliferation and the expression of transcripts known to be induced by systemic GH in the hippocampus. Cellular proliferation was examined by 5-bromo-2'-deoxyuridine immunohistochemistry. Quantitative PCR and western blots were performed. Although robustly expressed, bGH-Tg did not increase either cell proliferation or survival. However, bGH-Tg modestly increased Igf1 and Gfap mRNAs, whereas other GH-associated transcripts were unaffected, i.e. the GH receptor (Ghr), IGF1 receptor (Igf1r), 2',3'-cyclic nucleotide 3'-phosphodiesterase (Cnp), ionotropic glutamate receptor 2a (Nr2a (Grin2a)), opioid receptor delta (Dor), synapse-associated protein 90/postsynaptic density-95-associated protein (Sapap2 (Dlgap2)), haemoglobin beta (Hbb) and glutamine synthetase (Gs (Glul)). However, IGF1R was correlated with the expression of Dor, Nr2a, Sapap2, Gs and Gfap. In summary, although local bGH expression was robust, it activated local IGF1 very modestly, which is probably the reason for the low response of previous GH-associated response parameters. This would, in turn, indicate that hippocampal GH is less important than endocrine GH. However, as most transcripts were correlated with the expression of IGF1R, there is still a possibility for endogenous circulating or local GH to act via IGF1R signalling. Possible reasons for the relative bio-inactivity of bGH include the bell-shaped dose-response curve and cell-specific expression of bGH.
Assuntos
Regulação da Expressão Gênica/fisiologia , Hormônio do Crescimento/metabolismo , Hipocampo/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Animais , Peso Corporal , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Proliferação de Células , Hormônio do Crescimento/genética , Masculino , Camundongos , Camundongos Transgênicos , Neurônios/citologia , Neurônios/metabolismo , Tamanho do Órgão , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.
Assuntos
Acromegalia/metabolismo , Apoptose/fisiologia , Cardiomiopatias/metabolismo , Miocárdio/metabolismo , Transdução de Sinais/fisiologia , Acromegalia/patologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Cardiomiopatias/patologia , Bovinos , Camundongos , Camundongos Transgênicos , Miocárdio/patologiaRESUMO
The aim of the present study was to investigate the short- and long-term effects of a high-fat Western diet (WD) on intake, storage, expenditure, and fecal loss of energy as well as effects on locomotor activity and thermogenesis. WD for only 24 h resulted in a marked physiological shift in energy homeostasis, including increased body weight gain, body fat, and energy expenditure (EE) but an acutely lowered locomotor activity. The acute reduction in locomotor activity was observed after only 3-5 h on WD. The energy intake and energy absorption were increased during the first 24 h, lower after 72 h, and normalized between 7 and 14 days on WD compared with mice given chow diet. Core body temperature and EE was increased between 48 and 72 h but normalized after 21 days on WD. These changes paralleled plasma T(3) levels and uncoupling protein-1 expression in brown adipose tissue. After 21 days of WD, energy intake and absorption, EE, and body temperature were normalized. In contrast, the locomotor activity was reduced and body weight gain was increased over the entire 21-day study period on WD. Calculations based on the correlation between locomotor activity and EE in 2-h intervals at days 21-23 indicated that a large portion of the higher body weight gain in the WD group could be attributed to the reduced locomotor activity. In summary, an acute and persisting decrease in locomotor activity is most important for the effect of WD on body weight gain and obesity in mice.