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1.
Front Public Health ; 11: 1265323, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37942255

RESUMO

Introduction: Even using well-established technology assessment processes, the basis of the decisions on drug price and reimbursement are sometimes perceived as poorly informed and sometimes may be seen as disconnected from value. The literature remains inconclusive about how Health Technology Assessment Bodies (HTAb) should report the determinants of their decisions. This study evaluates the relationship between oncology and hematology drug list prices and structured value parameters at the time of reimbursement decision in Spain. Methods: The study includes all new onco-hematological products (22), with a first indication authorized between January 2017 and December 2019 in Spain and pricing decisions published up until October 2022. For each product, 56 contextual and non-contextual indicators reflecting the structured multiple criteria decision analysis (MCDA) - Evidence-based Decision-Making (EVIDEM) framework were measured. The relationship between prices and the MCDA-EVIDEM framework was explored using univariate statistical analyses. Results: Higher prices were observed when the standard of care included for combinations, if there were references to long-lasting responses, for fixed-duration treatment compared to treatment until progression and treatment with lower frequencies of administration; lower prices were observed for oral administration compared to other routes of administration. Statistically significant associations were observed between prices and the median duration of treatment, the impact on patient autonomy, the ease of use of the drug, and the recommendations of experts. Discussion: The study suggests that indicators related to the type of standard of care, references to long-lasting responders, the convenience of the use of the drug, and the impact of treatment on patient autonomy, as well as contextual indicators such as the existence of previous clinical consensus, are factors in setting oncology drug prices in Spain. The implementation of MCDA-EVIDEM methodologies may be useful to capture the influence on pricing decisions of additional factors not included in legislation or consolidated assessment frameworks such as the European Network for Health Technology Assessment (EunetHTA) core model. It may be opportune to consider this in the upcoming revision of the Spanish regulation for health technology assessments and pricing and reimbursement procedures.


Assuntos
Preparações Farmacêuticas , Humanos , Espanha , Custos e Análise de Custo , Consenso
2.
Redox Biol ; 54: 102353, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35777200

RESUMO

Metabolic plasticity is the ability of a biological system to adapt its metabolic phenotype to different environmental stressors. We used a whole-body and tissue-specific phenotypic, functional, proteomic, metabolomic and transcriptomic approach to systematically assess metabolic plasticity in diet-induced obese mice after a combined nutritional and exercise intervention. Although most obesity and overnutrition-related pathological features were successfully reverted, we observed a high degree of metabolic dysfunction in visceral white adipose tissue, characterized by abnormal mitochondrial morphology and functionality. Despite two sequential therapeutic interventions and an apparent global healthy phenotype, obesity triggered a cascade of events in visceral adipose tissue progressing from mitochondrial metabolic and proteostatic alterations to widespread cellular stress, which compromises its biosynthetic and recycling capacity. In humans, weight loss after bariatric surgery showed a transcriptional signature in visceral adipose tissue similar to our mouse model of obesity reversion. Overall, our data indicate that obesity prompts a lasting metabolic fingerprint that leads to a progressive breakdown of metabolic plasticity in visceral adipose tissue.


Assuntos
Resistência à Insulina , Tecido Adiposo/metabolismo , Animais , Homeostase , Gordura Intra-Abdominal/metabolismo , Camundongos , Obesidade/genética , Obesidade/metabolismo , Proteômica
3.
Mol Metab ; 37: 100984, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32229246

RESUMO

OBJECTIVE: Pancreatic ß-cell failure is central to the development and progression of type 2 diabetes (T2D). The aggregation of human islet amyloid polypeptide (hIAPP) has been associated with pancreatic islet inflammation and dysfunction in T2D. Alpha1-antitrypsin (AAT) is a circulating protease inhibitor with anti-inflammatory properties. Here, we sought to investigate the potential therapeutic effect of AAT treatment in a mouse model characterized by hIAPP overexpression in pancreatic ß-cells. METHODS: Mice overexpressing hIAPP (hIAPP-Tg) in pancreatic ß-cells were used as a model of amyloid-induced ß-cell dysfunction. Glucose homeostasis was evaluated by glucose tolerance tests and insulin secretion assays. Apoptosis and amyloid formation was assessed in hIAPP-Tg mouse islets cultured at high glucose levels. Dissociated islet cells were cocultured with macrophages obtained from the peritoneal cavity. RESULTS: Nontreated hIAPP-Tg mice were glucose intolerant and exhibited impaired insulin secretion. Interestingly, AAT treatment improved glucose tolerance and restored the insulin secretory response to glucose in hIAPP-Tg mice. Moreover, AAT administration normalized the expression of the essential ß-cell genes MafA and Pdx1, which were downregulated in pancreatic islets from hIAPP-Tg mice. AAT prevented the formation of amyloid deposits and apoptosis in hIAPP-Tg islets cultured at high glucose concentrations. Since islet macrophages mediate hIAPP-induced ß-cell dysfunction, we investigated the effect of AAT in cocultures of macrophages and islet cells. AAT prevented hIAPP-induced ß-cell apoptosis in these cocultures without reducing the hIAPP-induced secretion of IL-1ß by macrophages. Remarkably, AAT protected ß-cells against the cytotoxic effects of conditioned medium from hIAPP-treated macrophages. Similarly, AAT also abrogated the cytotoxic effects of exogenous proinflammatory cytokines on pancreatic ß-cells. CONCLUSIONS: These results demonstrate that treatment with AAT improves glucose homeostasis in mice overexpressing hIAPP and protects pancreatic ß-cells from the cytotoxic actions of hIAPP mediated by macrophages. These results support the use of AAT-based therapies to recover pancreatic ß-cell function for the treatment of T2D.


Assuntos
Células Secretoras de Insulina/fisiologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , alfa 1-Antitripsina/metabolismo , Amiloide/metabolismo , Animais , Apoptose , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Glucose/metabolismo , Intolerância à Glucose/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/fisiologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , alfa 1-Antitripsina/genética
4.
Appl Health Econ Health Policy ; 18(1): 5-16, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31696433

RESUMO

The potential benefits of early patient access to new medicines in areas of high unmet medical need are recognised, but uncertainties concerning effectiveness, safety and added value when new medicines are authorised, and subsequently funded based on initial preliminary data only, have important implications. In 2016 olaratumab received accelerated conditional approval from both the European Medicines Agency and the US Food and Drug Administration for the treatment of soft-tissue sarcoma, based on the claims of a substantial reduction in the risk of death with an 11.8-month improvement in median overall survival in a phase II trial in combination with doxorubicin vs. doxorubicin alone. The failure to confirm these benefits in the post-authorisation pivotal trial has highlighted key concerns regarding early access and conditional approvals for new medicines. Concerns include potentially considerable clinical and economic costs, so that patients may have received suboptimal treatment and any money spent has foregone the opportunity to improve access to effective treatments. As a result, it seems reasonable to reconsider current marketing authorisation models and approaches. Potential pathways forward include closer collaboration between regulators, pharmaceutical companies and payers to enhance the generation of rapid and comparative confirmatory trials in a safe and fair manner, with minimal patient exposure as required to achieve robust evidence. Additionally, it may be time to review early access systems, and to explore new avenues regarding who should pay or part pay for new treatments whilst information is being collected as part of any obligations for conditional marketing authorisation. Greater co-operation between countries regarding the collection of data in routine clinical care, and further research on post-marketing data analysis and interpretation, may also contribute to improved appraisal and continued access to new innovative cancer treatments.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/normas , Antineoplásicos/uso terapêutico , Doxorrubicina/uso terapêutico , Aprovação de Drogas , Neoplasias/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
Mol Cell Endocrinol ; 477: 48-56, 2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29883690

RESUMO

Overexpression of the X-linked inhibitor of apoptosis (XIAP) prevents islet allograft rejection. We constructed an adeno-associated virus expressing XIAP driven by the rat insulin promoter (dsAAV8-RIP-XIAP) for long-term beta-cell gene expression in vivo. Pancreatic delivery of dsAAV8-RIP-XIAP prevented autoimmune diabetes in 70% of non-obese diabetic (NOD) mice, associated with decreased insulitis. Islets from Balb/c mice transduced with dsAAV8-RIP-XIAP were protected following transplantation into streptozotocin (STZ)-diabetic Bl/6 recipients, associated with decreased graft infiltration. Interestingly, dsAAV8-RIP-XIAP transduction induced expression of lactate dehydrogenase (LDHA) and monocarboxylate transporter 1 (MCT1), two genes normally suppressed in beta cells and involved in production and release of lactate, a metabolite known to suppress local immune responses. Transduction of Balb/c islets with AAV8-RIP-LDHA-MCT1 tended to prolong allograft survival following transplant into STZ-diabetic Bl/6 recipients. These findings suggest that XIAP has therapeutic potential in autoimmune diabetes and raise the possibility that local lactate production may play a role in XIAP-mediated immunomodulation.


Assuntos
Aloenxertos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Rejeição de Enxerto/prevenção & controle , Imunomodulação , Células Secretoras de Insulina/metabolismo , Transplante das Ilhotas Pancreáticas , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Aloenxertos/efeitos dos fármacos , Aloenxertos/metabolismo , Animais , Diabetes Mellitus Tipo 1/patologia , Glucose/farmacologia , Rejeição de Enxerto/imunologia , Humanos , Tolerância Imunológica/efeitos dos fármacos , Imunomodulação/efeitos dos fármacos , Injeções , Insulina/genética , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/biossíntese , Camundongos , Camundongos Endogâmicos NOD , Transportadores de Ácidos Monocarboxílicos/metabolismo , Ratos , Simportadores/metabolismo
6.
Br J Clin Pharmacol ; 84(5): 1013-1019, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29370449

RESUMO

AIMS: The parallel regulatory-health technology assessment scientific advice (PSA) procedure allows manufacturers to receive simultaneous feedback from both EU regulators and health technology assessment (HTA) bodies on development plans for new medicines. The primary objective of the present study is to investigate whether PSA is integrated in the clinical development programmes for which advice was sought. METHODS: Contents of PSA provided by regulators and HTA bodies for each procedure between 2010 and 2015 were analysed. The development of all clinical studies for which PSA had been sought was tracked using three different databases. The rate of uptake of the advice provided by regulators and HTA bodies was assessed on two key variables: comparator/s and primary endpoint. RESULTS: In terms of uptake of comparator recommendations at the time of PSA in the actual development, our analysis showed that manufacturers implemented comparators to address both the needs of regulators and of at least one HTA body in 12 of 21 studies. For primary endpoints, in all included studies manufacturers addressed both the needs of the regulators and at least one HTA body. CONCLUSIONS: One of the key findings of this analysis is that manufacturers tend to implement changes to the development programme based on both regulatory and HTA advice with regards to the choice of primary endpoint and comparator. It also confirms the challenging choice of the study comparator, for which manufacturers seem to be more inclined to satisfy the regulatory advice. Continuous research efforts in this area are of paramount importance from a public health perspective.


Assuntos
Desenvolvimento de Medicamentos/estatística & dados numéricos , Indústria Farmacêutica/estatística & dados numéricos , Regulamentação Governamental , Avaliação da Tecnologia Biomédica/estatística & dados numéricos , Humanos
7.
FASEB J ; 31(12): 5296-5306, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28821639

RESUMO

Human islet amyloid polypeptide (hIAPP) aggregation is associated with ß-cell dysfunction and death in type 2 diabetes (T2D). we aimed to determine whether in vivo treatment with chemical chaperone 4-phenylbutyrate (PBA) ameliorates hIAPP-induced ß-cell dysfunction and islet amyloid formation. Oral administration of PBA in hIAPP transgenic (hIAPP Tg) mice expressing hIAPP in pancreatic ß cells counteracted impaired glucose homeostasis and restored glucose-stimulated insulin secretion. Moreover, PBA treatment almost completely prevented the transcriptomic alterations observed in hIAPP Tg islets, including the induction of genes related to inflammation. PBA also increased ß-cell viability and improved insulin secretion in hIAPP Tg islets cultured under glucolipotoxic conditions. Strikingly, PBA not only prevented but even reversed islet amyloid deposition, pointing to a direct effect of PBA on hIAPP. This was supported by in silico calculations uncovering potential binding sites of PBA to monomeric, dimeric, and pentameric fibrillar structures, and by in vitro assays showing inhibition of hIAPP fibril formation by PBA. Collectively, these results uncover a novel beneficial effect of PBA on glucose homeostasis by restoring ß-cell function and preventing amyloid formation in mice expressing hIAPP in ß cells, highlighting the therapeutic potential of PBA for the treatment of T2D.-Montane, J., de Pablo, S., Castaño, C., Rodríguez-Comas, J., Cadavez, L., Obach, M., Visa, M., Alcarraz-Vizán, G., Sanchez-Martinez, M., Nonell-Canals, A., Parrizas, M., Servitja, J.-M., Novials, A. Amyloid-induced ß-cell dysfunction and islet inflammation are ameliorated by 4-phenylbutyrate (PBA) treatment.


Assuntos
Amiloide/toxicidade , Células Secretoras de Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Fenilbutiratos/farmacologia , Animais , Teste de Tolerância a Glucose , Humanos , Imuno-Histoquímica , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/ultraestrutura , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Ilhotas Pancreáticas/citologia , Masculino , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Reação em Cadeia da Polimerase em Tempo Real
8.
Mol Cell Endocrinol ; 420: 57-65, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26607804

RESUMO

Human islet amyloid polypeptide (hIAPP) is the major component of amyloid deposits in islets of type 2 diabetic patients. hIAPP misfolding and aggregation is one of the factors that may lead to ß-cell dysfunction and death. Endogenous chaperones are described to be important for the folding and functioning of proteins. Here, we examine the effect of the endoplasmic reticulum chaperone protein disulfide isomerase (PDI) on ß-cell dysfunction. Among other chaperones, PDI was found to interact with hIAPP in human islet lysates. Furthermore, intrinsically recovered PDI levels were able to restore the effect of high glucose- and palmitate-induced ß-cell dysfunction by increasing 3.9-fold the glucose-stimulated insulin secretion levels and restoring insulin content up to basal control values. Additionally, PDI transduction decreased induced apoptosis by glucolipotoxic conditions. This approach could reveal a new therapeutic target and aid in the development of strategies to improve ß-cell dysfunction in type 2 diabetic patients.


Assuntos
Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Amiloide/metabolismo , Animais , Apoptose/efeitos dos fármacos , Glucose/farmacologia , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Camundongos Transgênicos , Chaperonas Moleculares/metabolismo , Ácido Palmítico/farmacologia , Ligação Proteica/efeitos dos fármacos , Extratos de Tecidos/metabolismo , Transdução Genética
9.
Cell Transplant ; 24(10): 2143-54, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26423995

RESUMO

Manipulation of regulatory T cell (Treg) migration by islet expression of the chemokine CCL22 prevents diabetes in NOD mice and delays recurrent autoimmunity in syngeneic islet transplants. We sought to determine whether attracting Tregs with CCL22 also prevents islet allograft rejection. Isolated Bl/6 mouse islets were transduced overnight with adenovirus expressing CCL22 (Ad-CCL22) downstream of the CMV promoter. Islets were transplanted under the renal capsule of Balb/c recipients made diabetic by streptozotocin. To assess immunologic tolerance, graft-bearing kidneys from recipients of CCL22-expressing islet grafts were removed, and mice received a second transplant of naive islets from the same donor strain or third-party islets into the contralateral kidney. Adenoviral expression of CCL22 conferred prolonged protection of islet allografts in MHC-mismatched, diabetic recipients, maintaining normoglycemia in 75% of recipients for at least 80 days. Increased frequency of Treg cells was observed in islet grafts transduced with Ad-CCL22 compared with untreated grafts. Normoglycemic recipients of CCL22-expressing islet grafts showed complete absence of antidonor antibodies and no lymphocyte proliferation after exposure to donor splenocytes. After removal of the primary graft at day 80, mice that received a second transplant with untreated islets from the same donor strain did not reject the grafts, suggesting the development of tolerance. Expression of CCL22 recruits Treg cells to transplanted islets, prevents activation of alloreactive T-cells and islet allograft failure and induces alloantigen-specific tolerance. Manipulation of Treg cells by CCL22 in transplanted islets may be a novel therapeutic strategy for diabetes.


Assuntos
Aloenxertos/imunologia , Quimiocina CCL22/imunologia , Sobrevivência de Enxerto/imunologia , Tolerância Imunológica/imunologia , Transplante das Ilhotas Pancreáticas/imunologia , Linfócitos T Reguladores/imunologia , Animais , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/terapia , Isoantígenos/imunologia , Camundongos , Tolerância ao Transplante/imunologia , Transplante Homólogo/métodos
10.
J Biol Chem ; 290(27): 16772-85, 2015 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-25971976

RESUMO

The human insulin-like growth factor 2 (IGF2) and insulin genes are located within the same genomic region. Although human genomic studies have demonstrated associations between diabetes and the insulin/IGF2 locus or the IGF2 mRNA-binding protein 2 (IGF2BP2), the role of IGF2 in diabetes pathogenesis is not fully understood. We previously described that transgenic mice overexpressing IGF2 specifically in ß-cells (Tg-IGF2) develop a pre-diabetic state. Here, we characterized the effects of IGF2 on ß-cell functionality. Overexpression of IGF2 led to ß-cell dedifferentiation and endoplasmic reticulum stress causing islet dysfunction in vivo. Both adenovirus-mediated overexpression of IGF2 and treatment of adult wild-type islets with recombinant IGF2 in vitro further confirmed the direct implication of IGF2 on ß-cell dysfunction. Treatment of Tg-IGF2 mice with subdiabetogenic doses of streptozotocin or crossing these mice with a transgenic model of islet lymphocytic infiltration promoted the development of overt diabetes, suggesting that IGF2 makes islets more susceptible to ß-cell damage and immune attack. These results indicate that increased local levels of IGF2 in pancreatic islets may predispose to the onset of diabetes. This study unravels an unprecedented role of IGF2 on ß-cells function.


Assuntos
Diabetes Mellitus/genética , Fator de Crescimento Insulin-Like II/genética , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Animais , Desdiferenciação Celular , Linhagem Celular Tumoral , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Humanos , Insulina/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ratos
11.
Diabetes ; 61(11): 2851-61, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22961079

RESUMO

Type 2 diabetes (T2D) results from insulin resistance and inadequate insulin secretion. Insulin resistance initially causes compensatory islet hyperplasia that progresses to islet disorganization and altered vascularization, inflammation, and, finally, decreased functional ß-cell mass and hyperglycemia. The precise mechanism(s) underlying ß-cell failure remain to be elucidated. In this study, we show that in insulin-resistant high-fat diet-fed mice, the enhanced islet vascularization and inflammation was parallel to an increased expression of vascular endothelial growth factor A (VEGF). To elucidate the role of VEGF in these processes, we have genetically engineered ß-cells to overexpress VEGF (in transgenic mice or after adeno-associated viral vector-mediated gene transfer). We found that sustained increases in ß-cell VEGF levels led to disorganized, hypervascularized, and fibrotic islets, progressive macrophage infiltration, and proinflammatory cytokine production, including tumor necrosis factor-α and interleukin-1ß. This resulted in impaired insulin secretion, decreased ß-cell mass, and hyperglycemia with age. These results indicate that sustained VEGF upregulation may participate in the initiation of a process leading to ß-cell failure and further suggest that compensatory islet hyperplasia and hypervascularization may contribute to progressive inflammation and ß-cell mass loss during T2D.


Assuntos
Ilhotas Pancreáticas/irrigação sanguínea , Ilhotas Pancreáticas/metabolismo , Neovascularização Patológica/metabolismo , Estado Pré-Diabético/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/biossíntese , Animais , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica/efeitos adversos , Progressão da Doença , Fibrose , Técnicas de Transferência de Genes , Hiperplasia , Resistência à Insulina , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neovascularização Patológica/imunologia , Neovascularização Patológica/patologia , Estado Pré-Diabético/etiologia , Estado Pré-Diabético/imunologia , Estado Pré-Diabético/patologia , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Biochem J ; 442(2): 345-56, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22115192

RESUMO

PFKFB (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase) catalyses the synthesis and degradation of Fru-2,6-P2 (fructose-2,6-bisphosphate), a key modulator of glycolysis and gluconeogenesis. The PFKFB3 gene is extensively involved in cell proliferation owing to its key role in carbohydrate metabolism. In the present study we analyse its mechanism of regulation by progestins in breast cancer cells. We report that exposure of T47D cells to synthetic progestins (ORG2058 or norgestrel) leads to a rapid increase in Fru-2,6-P2 concentration. Our Western blot results are compatible with a short-term activation due to PFKFB3 isoenzyme phosphorylation and a long-term sustained action due to increased PFKFB3 protein levels. Transient transfection of T47D cells with deleted gene promoter constructs allowed us to identify a PRE (progesterone-response element) to which PR (progesterone receptor) binds and thus transactivates PFKFB3 gene transcription. PR expression in the PR-negative cell line MDA-MB-231 induces endogenous PFKFB3 expression in response to norgestrel. Direct binding of PR to the PRE box (-3490 nt) was confirmed by ChIP (chromatin immunoprecipiation) experiments. A dual mechanism affecting PFKFB3 protein and gene regulation operates in order to assure glycolysis in breast cancer cells. An immediate early response through the ERK (extracellular-signal-regulated kinase)/RSK (ribosomal S6 kinase) pathway leading to phosphorylation of PFKFB3 on Ser461 is followed by activation of mRNA transcription via cis-acting sequences on the PFKFB3 promoter.


Assuntos
Neoplasias da Mama/metabolismo , Fosfofrutoquinase-2/metabolismo , Congêneres da Progesterona/farmacologia , Sequência de Bases , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases , Norgestrel/farmacologia , Fosfofrutoquinase-2/genética , Pregnenodionas/farmacologia , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Receptores de Progesterona/metabolismo
13.
Biochem Biophys Res Commun ; 367(4): 748-54, 2008 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-18191036

RESUMO

The bifunctional enzyme 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK-2) catalyzes the synthesis and degradation of fructose 2,6-bisphosphate (Fru-2,6-P(2)), a signalling molecule that controls the balance between glycolysis and gluconeogenesis in several cell types. Four genes, designated Pfkfb1-4, code several PFK-2 isozymes that differ in their kinetic properties, molecular masses, and regulation by protein kinases. In rat tissues, Pfkfb3 gene accounts for eight splice variants and two of them, ubiquitous and inducible PFK-2 isozymes, have been extensively studied and related to cell proliferation and tumour metabolism. Here, we characterize a new kidney- and liver-specific Pfkfb3 isozyme, a product of the RB2K3 splice variant, and demonstrate that its expression, in primary cultured hepatocytes, depends on hepatic cell proliferation and dedifferentiation. In parallel, our results provide further evidence that ubiquitous PFK-2 is a crucial isozyme in supporting growing and proliferant cell metabolism.


Assuntos
Hepatócitos/citologia , Hepatócitos/enzimologia , Rim/citologia , Rim/enzimologia , Fosfofrutoquinase-2/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Regulação para Baixo , Isoenzimas/metabolismo , Masculino , Especificidade de Órgãos , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
14.
Biochem Biophys Res Commun ; 365(2): 291-7, 2008 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-17991424

RESUMO

Fructose 2,6-bisphosphate (Fru-2,6-P2) is an important metabolite that controls glycolytic and gluconeogenic pathways in several cell types. Its synthesis and degradation are catalyzed by the bifunctional enzyme 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK-2). Four genes, designated Pfkfb1-4, codify the different PFK-2 isozymes. The Pfkfb3 gene product, ubiquitous PFK-2 (uPFK-2), has the highest kinase/bisphosphatase activity ratio and is associated with proliferation and tumor metabolism. A transgenic mouse model that overexpresses uPFK-2 under the control of the phosphoenolpyruvate carboxykinase promoter was designed to promote sustained and elevated Fru-2,6-P2 levels in the liver. Our results demonstrate that in diet-induced obesity, high Fru-2,6-P2 levels in transgenic livers caused changes in hepatic gene expression profiles for key gluconeogenic and lipogenic enzymes, as well as an accumulation of lipids in periportal cells, and weight gain.


Assuntos
Fígado/fisiologia , Fosfofrutoquinase-2/metabolismo , Aumento de Peso/fisiologia , Animais , Camundongos , Camundongos Transgênicos , Fosfofrutoquinase-2/genética , Regulação para Cima
15.
J Biol Chem ; 279(51): 53562-70, 2004 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-15466858

RESUMO

The up-regulation of glycolysis to enhance the production of energy under reduced pO(2) is a hallmark of the hypoxic response. A key regulator of glycolytic flux is fructose-2,6-bisphosphate, and its steady state concentration is regulated by the action of different isozymes product of four genes (pfkfb1-4). pfkfb3 has been found in proliferating cells and tumors, being induced by hypoxia. To understand the organization of cis-acting sequences that are responsible for the oxygen-regulated pfkfb3 gene, we have studied its 5'-flanking region. Extensive analysis of the 5' pfkfb3 promoter sequence revealed the presence of putative consensus binding sites for various transcription factors that could play an important role in pfkfb3 gene regulation. These DNA consensus sequences included estrogen receptor, hypoxia response element (HRE), early growth response, and specific protein 1 putative binding sites. Promoter deletion analysis as well as putative HREs sequences (wild type and mutated) fused to a c-fos minimal promoter unit constructs demonstrate that the sequence located from -1269 to -1297 relative to the start site is required for hypoxia-inducible factor 1 (HIF-1) induction. The effective binding of HIF-1 transcription factor to the HREs at -1279 and -1288 was corroborated by electrophoretic mobility shift assay and biotinylated oligonucleotide pull-down. In addition, HIF-1alpha null mouse embryo fibroblasts transfected with a full-length pfkfb3 promoter-luciferase reporter construct further demonstrated that HIF-1 protein was critically involved for hypoxia transactivation of this gene. Altogether, these results demonstrate that pfkfb3 is a hypoxia-inducible gene that is stimulated through HIF interaction with the consensus HRE site in its promoter region.


Assuntos
Hipóxia Celular/fisiologia , Regiões Promotoras Genéticas , Proteínas/genética , Proteínas/fisiologia , Fatores de Transcrição/química , Animais , Sítios de Ligação , Biotinilação , Western Blotting , Linhagem Celular , Proliferação de Células , Cobalto/química , Desferroxamina/química , Elementos Facilitadores Genéticos , Frutosedifosfatos/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Genes Reporter , Glicina/química , Humanos , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Quelantes de Ferro/farmacologia , Luciferases/metabolismo , Camundongos , Modelos Genéticos , Oligonucleotídeos/química , Oxigênio/metabolismo , Fosfofrutoquinase-2 , Plasmídeos/metabolismo , Ligação Proteica , Isoformas de Proteínas , Estrutura Terciária de Proteína , Interferência de RNA , Receptores de Estrogênio , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Software , Fatores de Tempo , Transcrição Gênica , Ativação Transcricional , Transfecção , Regulação para Cima
16.
Cryobiology ; 49(2): 190-4, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15351690

RESUMO

We have investigated different signaling molecules that could be activated by temperature acclimation and hypoxia, using an experimental approach consisting in submerging frogs in a water-filled box maintained at 2-4 degrees C at ambient oxygen levels or supplied with 98% N2:2% CO2 for normoxia or hypoxia conditions, respectively. The results obtained showed no significant changes in the expression of heat shock protein 70. The phosphorylation state of AMP-dependent activated protein kinase, the down-stream component of a protein kinase cascade that acts as an intracellular energy sensor, was significantly increased in both experimental conditions, showing higher values in the absence of oxygen. Similarly, the phosphorylation state of one of its known substrates, elongation factor 2, was also increased, consistent with the arrest of protein synthesis. These results point out an important role of this kinase, adjusting the rates of ATP-consuming and ATP-generating pathways, in the survival strategies to hypoxia and hypothermia.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Hipotermia/enzimologia , Hipóxia/enzimologia , Fígado/enzimologia , Ranidae/metabolismo , Aclimatação , Animais , Ativação Enzimática , Cinética , Masculino , Transdução de Sinais
17.
FEBS Lett ; 550(1-3): 23-9, 2003 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-12935880

RESUMO

6-Phosphofructo-2-kinase catalyzes the synthesis and degradation of fructose 2,6-bisphosphate, activator of phosphofructokinase-1 and inhibitor of fructose 1,6-bisphosphatase. These properties confer to this bifunctional enzyme a key role in the control of glycolysis and gluconeogenesis. Several mammalian isozymes generated by alternative splicing from four genes, designated pfkfb1-4, have been identified. The results presented in this study demonstrate the expression of the pfkfb3 gene in C2C12 cells and its downregulation during myogenic cell differentiation. We also show that the decrease of ubiquitous 6-phosphofructo-2-kinase isozyme levels, product of pfkfb3 gene, is due to its enhanced degradation through the ubiquitin-proteasome proteolytic pathway.


Assuntos
Diferenciação Celular/fisiologia , Cisteína Endopeptidases/metabolismo , Complexos Multienzimáticos/metabolismo , Mioblastos/metabolismo , Fosfofrutoquinase-2/metabolismo , Ubiquitina/metabolismo , Animais , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Regulação Enzimológica da Expressão Gênica , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Leupeptinas/farmacologia , Complexos Multienzimáticos/antagonistas & inibidores , Mioblastos/citologia , Fosfofrutoquinase-2/genética , Complexo de Endopeptidases do Proteassoma , Proteínas/genética , Proteínas/metabolismo
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