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1.
Proc Natl Acad Sci U S A ; 115(8): 1789-1794, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29434038

RESUMO

Although the addition of the prosthetic group lipoate is essential to the activity of critical mitochondrial catabolic enzymes, its regulation is unknown. Here, we show that lipoylation of the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase (αKDH) complexes is a dynamically regulated process that is inhibited under hypoxia and in cancer cells to restrain mitochondrial respiration. Mechanistically, we found that the polymerase-δ interacting protein 2 (Poldip2), a nuclear-encoded mitochondrial protein of unknown function, controls the lipoylation of the pyruvate and α-KDH dihydrolipoamide acetyltransferase subunits by a mechanism that involves regulation of the caseinolytic peptidase (Clp)-protease complex and degradation of the lipoate-activating enzyme Ac-CoA synthetase medium-chain family member 1 (ACSM1). ACSM1 is required for the utilization of lipoic acid derived from a salvage pathway, an unacknowledged lipoylation mechanism. In Poldip2-deficient cells, reduced lipoylation represses mitochondrial function and induces the stabilization of hypoxia-inducible factor 1α (HIF-1α) by loss of substrate inhibition of prolyl-4-hydroxylases (PHDs). HIF-1α-mediated retrograde signaling results in a metabolic reprogramming that resembles hypoxic and cancer cell adaptation. Indeed, we observe that Poldip2 expression is down-regulated by hypoxia in a variety of cell types and basally repressed in triple-negative cancer cells, leading to inhibition of lipoylation of the pyruvate and α-KDH complexes and mitochondrial dysfunction. Increasing mitochondrial lipoylation by forced expression of Poldip2 increases respiration and reduces the growth rate of cancer cells. Our work unveils a regulatory mechanism of catabolic enzymes required for metabolic plasticity and highlights the role of Poldip2 as key during hypoxia and cancer cell metabolic adaptation.


Assuntos
Hipóxia/enzimologia , Neoplasias/enzimologia , Proteínas Nucleares/metabolismo , Oxigênio/metabolismo , Animais , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Complexo Cetoglutarato Desidrogenase/genética , Complexo Cetoglutarato Desidrogenase/metabolismo , Lipoilação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/enzimologia , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil , Ácido Tióctico/metabolismo
2.
Clin Exp Allergy ; 49(1): 82-91, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30204277

RESUMO

BACKGROUND: Reports of fatal anaphylaxis remain scarce because of the rarity of the condition and the fact that information is limited to a few countries. OBJECTIVE: Our objective was to investigate clinical and demographic characteristics and the causes of fatal anaphylaxis in Spain using two databases of cases of fatal anaphylaxis. METHODS: We analysed fatal anaphylaxis in a series from the Spanish hospital system and a series from the National Institute of Toxicology and Forensic Sciences (Instituto Nacional de Toxicología y Ciencias Forenses [INTCF]), which predominantly comprise extrahospital deaths. Deaths from the Spanish hospital system were retrieved from among all deaths occurring during 1998-2011 using codes related to anaphylaxis. Deaths due to anaphylaxis in the INTCF database during the same period were retrieved by 2 allergists, who identified cases in which anaphylaxis was a possible cause of death. A logistic regression model was constructed to predict the characteristics of fatal anaphylaxis in each database. RESULTS: The incidence of death by anaphylaxis in Spain using both databases was 0.25 (95% CI, 0.24-0.26) deaths per million person-years. The most frequent causes of death in the hospital system were drugs (46.1%), unknown causes (40.0%), and foods (10.4%); in the INTCF, the most common causes of death were drugs (47.2%), insect stings (30.6%), and foods (11.1%). The logistic regression model showed that fatal anaphylaxis due to unknown causes (OR 15.2, 95% CI 1.8-129.8) was more likely in the hospital database, whereas insect stings (OR 100, 95% CI 10-833.3) and previous atopic comorbidity (OR 15.2, 95% CI 6.3-33.3) were more likely in the INTCF database. CONCLUSIONS & CLINICAL RELEVANCE: The estimated frequency of fatal anaphylaxis in Spain was among the lowest reported. Future studies of fatal anaphylaxis should use databases from different origins in order to show the considerable heterogeneity in this type of death.


Assuntos
Anafilaxia/etiologia , Anafilaxia/mortalidade , Bases de Dados Factuais , Adulto , Feminino , Medicina Legal , Humanos , Masculino , Espanha/epidemiologia
3.
BMC Pregnancy Childbirth ; 19(1): 46, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691390

RESUMO

BACKGROUND: Advances in science and technology coupled with globalization are changing access to and utilization of reproductive health services. This includes the transnational phenomenon of families who use surrogate mothers to reproduce, with forms of altruistic and commercial surrogacy becoming more commonplace. Simultaneously, changes in law, regulation, and policy are necessary to protect surrogates, intended parents, and resulting children. These developments have been slow to adapt to challenges inherent to surrogacy arrangements, most specifically in low-and middle-income countries, including in South American countries. METHODS: We conducted an interdisciplinary non-systematic literature review and legal analysis of existing and pending policy, laws, and regulations related to commercial surrogacy arrangements in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay, and Venezuela. The review focused on articles that discussed topics of domestic and international law, policy, regulation, and governance related to commercial surrogacy. We queried PubMed, JSTOR, and Google Scholar for Spanish and English-language articles limited to those published between 2000 and 2016. RESULTS: Our literature and legal review found a wide variance in how different countries address the issue, including two (Brazil and Uruguay) that have issued guidance attempting to clarify the legality of commercial surrogacy, others who have introduced surrogacy-specific legislation, and a final group with no specific legal mechanisms in place. Our extracted legal case studies also indicate that courts have a hard time interpreting existing law and its applicability to surrogacy. The influence of Catholicism also played a role in the adoption of surrogacy and other advanced reproductive technology (ART)-related legislation. CONCLUSIONS: Changes in global infertility rates, the emergence of new family structures, and advancement of ART are factors that will influence future development of legal frameworks addressing surrogacy in South America. Despite a growing transnational market for commercial surrogacy in many of the countries examined, the current patchwork of policy does little to clarify what forms of surrogacy are legally permissible, nor do they adequately protect surrogates, intended parents, or the children themselves. This points to an urgent need for regional legal and policy harmonization specifically designed to align with public health and human rights principles.


Assuntos
Turismo Médico/legislação & jurisprudência , Mães Substitutas/legislação & jurisprudência , Direitos da Mulher/legislação & jurisprudência , Feminino , Direitos Humanos/legislação & jurisprudência , Humanos , Gravidez , Técnicas de Reprodução Assistida/legislação & jurisprudência , América do Sul
4.
Forensic Sci Med Pathol ; 15(3): 369-381, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31292823

RESUMO

Forensic series on fatal anaphylaxis are scarce, probably because the diagnosis of anaphylaxis is often complex and the incidence is low. We report on the medicolegal, demographic and histopathological characteristics of a series of sudden deaths which were investigated for anaphylaxis at the Spanish National Institute of Toxicology and Forensic Sciences (INTCF) over a 17-year period (1998-2015). A total of 122 undetermined sudden deaths from a high percentage of Spanish regions (81.5% of the total population) were sent to the INTCF with anaphylaxis as the suspected cause of death for histological, biochemical, and medicolegal investigation. Two certified allergists confirmed that 46 of the 122 cases were fatal anaphylaxis. The results indicated a median age of 51 years (IQR = 29) and a male predominance (76%). The main causes of anaphylaxis were drugs (41%), hymenoptera stings (33%), and food (13%). A previous allergic event had been reported in both food anaphylaxis (67%) and drug anaphylaxis (53%). The deaths occurred in health care settings (37%), at home (22%), and outside the home (26.09%). Histopathology data were available for 40 individuals. The most frequent autopsy findings were angioedema of the upper airways (50%), pulmonary edema (47.5%), atheromatosis of coronary vessels (32.5%), and pulmonary congestion (27.5%). Our findings for fatal anaphylaxis indicated a predominance of men, older age (≥50 years) and death in a health care setting (one-third of cases). Previous episodes had occurred in two-thirds of cases of food-induced anaphylaxis and in half of the cases of drug-induced anaphylaxis.


Assuntos
Anafilaxia/mortalidade , Anafilaxia/patologia , Angioedema/patologia , Animais , Mordeduras e Picadas/mortalidade , Cianose/patologia , Hipersensibilidade a Drogas/mortalidade , Feminino , Hipersensibilidade Alimentar/mortalidade , Humanos , Himenópteros , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Edema Pulmonar/patologia , Púrpura/patologia , Estudos Retrospectivos , Espanha/epidemiologia , Triptases/sangue
5.
J Neurosci ; 37(35): 8385-8398, 2017 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-28751457

RESUMO

The failure to undergo remyelination is a critical impediment to recovery in multiple sclerosis. Chondroitin sulfate proteoglycans (CSPGs) accumulate at demyelinating lesions creating a nonpermissive environment that impairs axon regeneration and remyelination. Here, we reveal a new role for 2-arachidonoylglycerol (2-AG), the major CNS endocannabinoid, in the modulation of CSPGs deposition in a progressive model of multiple sclerosis, the Theiler's murine encephalomyelitis virus-induced demyelinating disease. Treatment with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-AG degradation in the mouse CNS, modulates neuroinflammation and reduces CSPGs accumulation and astrogliosis around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. Inhibition of 2-AG hydrolysis augments the number of mature oligodendrocytes and increases MBP, leading to remyelination and functional recovery of mice. Our findings establish a mechanism for 2-AG promotion of remyelination with implications in axonal repair in CNS demyelinating pathologies.SIGNIFICANCE STATEMENT The deposition of chondroitin sulfate proteoglycans contributes to the failure in remyelination associated with multiple sclerosis. Here we unveil a new role for 2-arachidonoylglycerol, the major CNS endocannabinoid, in the modulation of chondroitin sulfate proteoglycan accumulation in Theiler's murine encephalomyelitis virus-induced demyelinating disease. The treatment during the chronic phase with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-arachidonoylglycerol degradation in the mouse CNS, modulates neuroinflammation and reduces chondroitin sulfate proteoglycan deposition around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. The increased 2-arachidonoylglycerol tone promotes remyelination in a model of progressive multiple sclerosis ameliorating motor dysfunction.


Assuntos
Ácidos Araquidônicos/farmacologia , Ácidos Araquidônicos/uso terapêutico , Endocanabinoides/farmacologia , Endocanabinoides/uso terapêutico , Glicerídeos/farmacologia , Glicerídeos/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/fisiopatologia , Fibras Nervosas Mielinizadas/efeitos dos fármacos , Fibras Nervosas Mielinizadas/patologia , Proteoglicanas/metabolismo , Animais , Agonistas de Receptores de Canabinoides/farmacologia , Agonistas de Receptores de Canabinoides/uso terapêutico , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Feminino , Camundongos , Esclerose Múltipla/patologia , Neurogênese/efeitos dos fármacos
6.
Am J Respir Cell Mol Biol ; 58(5): 648-657, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29182484

RESUMO

Pulmonary hypertension (PH) is a progressive disorder that causes significant morbidity and mortality despite existing therapies. PH pathogenesis is characterized by metabolic derangements that increase pulmonary artery smooth muscle cell (PASMC) proliferation and vascular remodeling. PH-associated decreases in peroxisome proliferator-activated receptor γ (PPARγ) stimulate PASMC proliferation, and PPARγ in coordination with PPARγ coactivator 1α (PGC1α) regulates mitochondrial gene expression and biogenesis. To further examine the impact of decreases in PPARγ expression on human PASMC (HPASMC) mitochondrial function, we hypothesized that depletion of either PPARγ or PGC1α perturbs mitochondrial structure and function to stimulate PASMC proliferation. To test this hypothesis, HPASMCs were exposed to hypoxia and treated pharmacologically with the PPARγ antagonist GW9662 or with siRNA against PPARγ or PGC1α for 72 hours. HPASMC proliferation (cell counting), target mRNA levels (qRT-PCR), target protein levels (Western blotting), mitochondria-derived H2O2 (confocal immunofluorescence), mitochondrial mass and fragmentation, and mitochondrial bioenergetic profiling were determined. Hypoxia or knockdown of either PPARγ or PGC1α increased HPASMC proliferation, enhanced mitochondria-derived H2O2, decreased mitochondrial mass, stimulated mitochondrial fragmentation, and impaired mitochondrial bioenergetics. Taken together, these findings provide novel evidence that loss of PPARγ diminishes PGC1α and stimulates derangements in mitochondrial structure and function that cause PASMC proliferation. Overexpression of PGC1α reversed hypoxia-induced HPASMC derangements. This study identifies additional mechanistic underpinnings of PH, and provides support for the notion of activating PPARγ as a novel therapeutic strategy in PH.


Assuntos
Hipertensão Pulmonar/metabolismo , Mitocôndrias Musculares/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , PPAR gama/metabolismo , Anilidas/farmacologia , Animais , Hipóxia Celular , Proliferação de Células , Células Cultivadas , Humanos , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Hipertensão Pulmonar/prevenção & controle , Camundongos Endogâmicos C57BL , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/patologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , PPAR gama/antagonistas & inibidores , PPAR gama/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Interferência de RNA
7.
Glia ; 66(7): 1447-1463, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29484707

RESUMO

The innate immune response is mediated by primary immune modulators such as cytokines and chemokines that together with immune cells and resident glia orchestrate CNS immunity and inflammation. Growing evidence supports that the endocannabinoid 2-arachidonoylglycerol (2-AG) exerts protective actions in CNS injury models. Here, we used the acute phase of Theiler's virus induced demyelination disease (TMEV-IDD) as a model of acute neuroinflammation to investigate whether 2-AG modifies the brain innate immune responses to TMEV and CNS leukocyte trafficking. 2-AG or the inhibition of its hydrolysis diminished the reactivity and number of microglia at the TMEV injection site reducing their morphological complexity and modulating them towards an anti-inflammatory state via CB2 receptors. Indeed, 2-AG dampened the infiltration of immune cells into the CNS and inhibited their egress from the spleen, resulting in long-term beneficial effects at the chronic phase of the disease. Intriguingly, it is not a generalized action over leukocytes since 2-AG increased the presence and suppressive potency of myeloid derived suppressor cells (MDSCs) in the brain resulting in higher apoptotic CD4+ T cells at the injection site. Together, these data suggest a robust modulatory effect in the peripheral and central immunity by 2-AG and highlight the interest of modulating endogenous cannabinoids to regulate CNS inflammatory conditions.


Assuntos
Ácidos Araquidônicos/metabolismo , Infecções por Cardiovirus/imunologia , Endocanabinoides/metabolismo , Glicerídeos/metabolismo , Inflamação/imunologia , Microglia/imunologia , Theilovirus , Animais , Ácidos Araquidônicos/administração & dosagem , Encéfalo/imunologia , Encéfalo/patologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Infecções por Cardiovirus/patologia , Modelos Animais de Doenças , Endocanabinoides/administração & dosagem , Feminino , Glicerídeos/administração & dosagem , Imunidade Inata/imunologia , Inflamação/patologia , Camundongos , Microglia/patologia , Monoacilglicerol Lipases/antagonistas & inibidores , Monoacilglicerol Lipases/metabolismo , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/metabolismo
8.
Bioconjug Chem ; 29(6): 2021-2027, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29733594

RESUMO

Serotonin (5-HT) modulates key aspects of the immune system. However, its precise function and the receptors involved in the observed effects have remained elusive. Among the different serotonin receptors, 5-HT1A plays an important role in the immune system given its presence in cells involved in both the innate and adaptive immune responses, but its actual levels of expression under different conditions have not been comprehensively studied due to the lack of suitable tools. To further clarify the role of 5-HT1A receptor in the immune system, we have developed a fluorescent small molecule probe that enables the direct study of the receptor levels in native cells. This probe allows direct profiling of the receptor expression in immune cells using flow cytometry. Our results show that important subsets of immune cells including human monocytes and dendritic cells express functional 5-HT1A and that its activation is associated with anti-inflammatory signaling. Furthermore, application of the probe to the experimental autoimmune encephalomyelitis model of multiple sclerosis demonstrates its potential to detect the specific overexpression of the 5-HT1A receptor in CD4+ T cells. Accordingly, the probe reported herein represents a useful tool whose use can be extended to study the levels of 5-HT1A receptor in ex vivo samples of different immune system conditions.


Assuntos
Compostos de Boro/química , Citometria de Fluxo/métodos , Corantes Fluorescentes/química , Receptor 5-HT1A de Serotonina/análise , Animais , Compostos de Boro/síntese química , Técnicas de Química Sintética , Células Dendríticas/química , Corantes Fluorescentes/síntese química , Humanos , Leucócitos Mononucleares/patologia , Camundongos , Monócitos/química , Esclerose Múltipla/patologia , Linfócitos T/química
9.
Biochem Biophys Res Commun ; 446(1): 410-6, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24613839

RESUMO

Incretin GLP-1 has important metabolic effects on several tissues, mainly through the regulation of glucose uptake and usage. One mechanism for increasing cell metabolism is modulating endoplasmic reticulum (ER)-mitochondria communication, as it allows for a more efficient transfer of Ca(2+) into the mitochondria, thereby increasing activity. Control of glucose metabolism is essential for proper vascular smooth muscle cell (VSMC) function. GLP-1 has been shown to produce varied metabolic actions, but whether it regulates glucose metabolism in VSMC remains unknown. In this report, we show that GLP-1 increases mitochondrial activity in the aortic cell line A7r5 by increasing ER-mitochondria coupling. GLP-1 increases intracellular glucose and diminishes glucose uptake without altering glycogen content. ATP, mitochondrial potential and oxygen consumption increase at 3h of GLP-1 treatment, paralleled by increased Ca(2+) transfer from the ER to the mitochondria. Furthermore, GLP-1 increases levels of Mitofusin-2 (Mfn2), an ER-mitochondria tethering protein, via a PKA-dependent mechanism. Accordingly, PKA inhibition and Mfn2 down-regulation prevented mitochondrial Ca(2+) increases in GLP-1 treated cells. Inhibiting both Ca(2+) release from the ER and Ca(2+) entry into mitochondria as well as diminishing Mfn2 levels blunted the increase in mitochondrial activity in response to GLP-1. Altogether, these results strongly suggest that GLP-1 increases ER-mitochondria communication in VSMC, resulting in higher mitochondrial activity.


Assuntos
Retículo Endoplasmático/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Mitocôndrias/metabolismo , Miócitos de Músculo Liso/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , GTP Fosfo-Hidrolases , Receptor do Peptídeo Semelhante ao Glucagon 1 , Glucose/metabolismo , Glicogênio/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Ratos , Receptores de Glucagon/genética , Receptores de Glucagon/metabolismo
10.
Angew Chem Int Ed Engl ; 53(50): 13765-70, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25298214

RESUMO

Monoacylglycerol lipase (MAGL) is the enzyme responsible for the inactivation of the endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL inhibitors show analgesic and tissue-protecting effects in several disease models. However, the few efficient and selective MAGL inhibitors described to date block the enzyme irreversibly, and this can lead to pharmacological tolerance. Hence, additional classes of MAGL inhibitors are needed to validate this enzyme as a therapeutic target. Here we report a potent, selective, and reversible MAGL inhibitor (IC50=0.18 µM) which is active in vivo and ameliorates the clinical progression of a multiple sclerosis (MS) mouse model without inducing undesirable CB1 -mediated side effects. These results support the interest in MAGL as a target for the treatment of MS.


Assuntos
Monoacilglicerol Lipases/antagonistas & inibidores , Esclerose Múltipla/tratamento farmacológico , Animais , Modelos Animais de Doenças , Inibidores Enzimáticos/uso terapêutico , Camundongos
11.
J Med Chem ; 67(12): 10306-10320, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38872300

RESUMO

Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvß1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, in silico modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvß1 relative to several other integrin isoforms measured. Azabenzimidazolone 25 demonstrated antifibrotic efficacy in an in vivo rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvß1 inhibition.


Assuntos
Desenho de Fármacos , Receptores de Vitronectina , Animais , Ratos , Humanos , Receptores de Vitronectina/antagonistas & inibidores , Receptores de Vitronectina/metabolismo , Relação Estrutura-Atividade , Cirrose Hepática/tratamento farmacológico , Modelos Moleculares , Descoberta de Drogas , Ratos Sprague-Dawley , Masculino , Cristalografia por Raios X , Benzimidazóis/farmacologia , Benzimidazóis/química , Benzimidazóis/síntese química
12.
Proc Natl Acad Sci U S A ; 107(48): 20672-7, 2010 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-20639468

RESUMO

Given the significance of carbohydrates in life, medicine, and industry, the development of simple and efficient de novo methods to synthesize carbohydrates are highly desirable. Organocatalytic asymmetric assembly reactions are powerful tools to rapidly construct molecules with stereochemical complexity from simple precursors. Here, we present a simple and robust methodology for the asymmetric synthesis of pyranose derivatives with talo- and manno- configurations from simple achiral precursors through organocatalytic asymmetric intermolecular Michael-Henry reaction sequences. In this process, (tert-butyldimethylsilyloxy)acetaldehyde 1 was successfully utilized in two ways: as a donor in a highly selective anti-Michael reaction and as an acceptor in a consecutive Henry reaction. Varied nitroolefins served as Michael acceptors and varied aldehydes substituted for 1 as Henry acceptors providing for the construction of a wide range of carbohydrates with up to 5 stereocenters. In these reactions, a catalyst-controlled Michael reaction followed by a substrate-controlled Henry reaction provided 3,4-dideoxytalose derivatives 6 in a highly stereoselective manner. The Henry reaction was affected by addition of a simple base such as triethylamine: A complex chiral base was not necessary. 3,4-Dideoxymannose derivatives 7 were produced by simply changing the base from triethylamine to 1,8-diazabicyclo[5.4.0]undec-7-ene. Extension of this methodology to a syn-Michael initiated sequence was also successful. A mechanistic discussion is provided to explain the unusual substrate-induced stereoselectivity of the Henry reaction.


Assuntos
Carboidratos/química , Carboidratos/síntese química , Modelos Químicos , Catálise , Cristalografia por Raios X , Lactonas/química , Manose/química
13.
Vasa ; 42(1): 8-16, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23385222

RESUMO

Differentiation of vascular smooth muscle cells (VSMC) is an essential process of vascular development. VSMC have biosynthetic, proliferative, and contractile roles in the vessel wall. Alterations in the differentiated state of the VSMC play a critical role in the pathogenesis of atherosclerosis and intimal hyperplasia, as well as in a variety of other human diseases, including hypertension, asthma, atherosclerosis and vascular aneurysm. This review provides an overview of the current state of knowledge of molecular mechanisms involved in controlling VSMC proliferation, with particular focus on glucose metabolism and its relationship with mitochondrial bioenergetics. Increased levels of glucose transporter 1 (GLUT1) are observed in VSMC after endothelial injury, suggesting a relationship between glucose uptake and VSMC proliferation. Mitochondrial dysfunction is a common feature in VSMC during atherosclerosis. Alterations in mitochondrial function can be produced by dysregulation of mitofusin-2, a small GTPase associated with mitochondrial fusion. Moreover, exacerbated proliferation was observed in VSMC from pulmonary arteries with hyperpolarized mitochondria and enhanced glycolysis/glucose oxidation ratio. Several lines of evidence highlight the relevance of glucose metabolism in the control of VSMC proliferation, indicating a new area to be explored in the control of vascular pathogenesis.


Assuntos
Aterosclerose/metabolismo , Proliferação de Células , Glucose/metabolismo , Mitocôndrias Musculares/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Aterosclerose/patologia , Metabolismo Energético , Humanos , Hiperplasia , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Estresse Oxidativo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
14.
Cancers (Basel) ; 14(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36010868

RESUMO

BACKGROUND: Cell-free DNA (cfDNA) concentrations have been described to be inversely correlated with prognosis in cancer. Mutations in HCC-associated driver genes in cfDNA have been reported, but their relation with patient's outcome has not been described. Our aim was to elucidate whether mutations found in cfDNA could be representative from those present in HCC tissue, providing the rationale to use the cfDNA to monitor HCC. METHODS: Tumoral tissue, paired nontumor adjacent tissue and blood samples were collected from 30 HCC patients undergoing curative therapies. Deep sequencing targeting HCC driver genes was performed. RESULTS: Patients with more than 2 ng/µL of cfDNA at diagnosis had higher mortality (mean OS 24.6 vs. 31.87 months, p = 0.01) (AUC = 0.782). Subjects who died during follow-up, had a significantly higher number of mutated genes (p = 0.015) and number of mutations (p = 0.015) on cfDNA. Number of mutated genes (p = 0.001), detected mutations (p = 0.001) in cfDNA and ratio (number of mutations/cfDNA) (p = 0.003) were significantly associated with recurrence. However, patients with a ratio (number of mutations/cfDNA) above 6 (long-rank p = 0.0003) presented a higher risk of recurrence than those with a ratio under 6. Detection of more than four mutations in cfDNA correlated with higher risk of death (long-rank p = 0.042). CONCLUSIONS: In summary, cfDNA and detection of prevalent HCC mutations could have prognostic implications in early-stage HCC patients.

15.
Brain Sci ; 12(7)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35884672

RESUMO

Background: Acute stroke care has greatly improved in recent decades. However, the increasing stroke mortality in low-to-middle income countries suggests that progress has not been reached completely by these populations. Here we present the analysis of the hospital phase of the first population-based stroke surveillance study. Methods: A daily hospital surveillance method was used to identify adult patients with acute stroke during 18 months in six hospitals. We abstracted data on demographics, vascular risk factors, neuroimaging-confirmed stroke types, and clinical data. Results: A total of 1361 adults with acute stroke were identified (mean age 69.2 years; 52% women) with transient ischemic attack (5.5%), acute ischemic stroke (68.6%), intracerebral hemorrhage (23.1%), cerebral venous thrombosis (0.2%), and undetermined stroke (2.6%). The main risk factors were hypertension (80.7%) and diabetes mellitus (47.6%). The usage rate of thrombolysis was 3.6%, in spite of the fact that 37.2% of acute ischemic stroke patients arrived in <4.5 h. The 30-day case fatality rate was 32.6%, higher in hemorrhagic than ischemic stroke. Conclusion: We identified limitations in acute stroke care in the Mexico City, including neuroimaging availability and thrombolysis usage. The door-to-door phase will help to depict the acute stroke burden in Mexico.

16.
J Am Chem Soc ; 133(32): 12354-7, 2011 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-21780763

RESUMO

Carbazolespirooxindole derivatives were synthesized in a high-yielding, atypically rapid, stereocontrolled Diels-Alder reaction catalyzed by a C(2)-symmetric bisthiourea organocatalyst. Simple precursors and mild conditions were used to construct carbazolespirooxindole derivatives with high enantiopurity and structural diversity under H-bonding catalysis. The practical approach recycles the organocatalyst and solvent. This simple and efficient operational procedure will allow diversity-oriented syntheses of this intriguing class of compounds.


Assuntos
Indóis/química , Catálise , Ligação de Hidrogênio , Indóis/síntese química , Estereoisomerismo , Tioureia/química
17.
Chemistry ; 17(4): 1283-93, 2011 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-21243696

RESUMO

Good to excellent stereoselectivities were achieved in the reductive cyclization (with Et(3)SiH/trimethylsilyl trifluoromethanesulfonate (TMSOTf)) of enantiopure hydroxy sulfinyl ketones en route to 2,5-cis-disubstituted tetrahydrofuran skeletons. Electrostatic effects of the exocyclic sulfoxide, which stabilized the reactive intermediate oxocarbenium conformations, were responsible for the observed stereocontrol. A model is proposed to explain the results. The use of this reaction and the asymmetric ß-ketosulfoxide reduction as key steps facilitated the total enantioselective synthesis of the natural ß-C-aryl glycoside (+)-goniothalesdiol.


Assuntos
Produtos Biológicos/química , Furanos/química , Metano/análogos & derivados , Sulfóxidos/química , Ciclização , Furanos/síntese química , Espectroscopia de Ressonância Magnética , Metano/química , Conformação Molecular , Estrutura Molecular , Estereoisomerismo
18.
Autophagy ; 17(12): 4305-4322, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33985412

RESUMO

ULK1 (unc-51 like autophagy activating kinase) has a central role in initiating macroautophagy/autophagy, a process that contributes to atherosclerosis and neointima hyperplasia, or excessive tissue growth that leads to vessel dysfunction. However, the role of ULK1 in neointima formation remains unclear. We aimed to determine how Ulk1 deletion affected neointima formation and to investigate the underlying mechanisms. We measured autophagy activity, vascular smooth muscle cell (VSMC) migration and neointima hyperplasia in cultured VSMCs and ligation-injured mouse carotid arteries from male wild-type (WT, C57BL/6 J) and VSMC-specific ulk1 knockout (ulk1 KO) mice. Carotid artery ligation in WT mice increased ULK1 protein expression, and concurrently increased autophagic flux and neointima formation. Treating human aortic smooth muscle cells (HASMCs) with PDGF (platelet derived growth factor) increased ULK1 expression, activated autophagy, and promoted cell migration. Further, smooth muscle cell-specific deletion of Ulk1 suppressed autophagy, inhibited VSMC migration, and impeded neointima hyperplasia. Mechanistically, Ulk1 deletion inhibited autophagic degradation of histone acetyltransferase protein KAT2A/GCN5 (K[lysine] acetyltransferase 2A), resulting in accumulation of KAT2A that directly acetylated TUBA/α-tubulin and subsequently increased protein levels of acetylated TUBA. The acetylation of TUBA increased microtubule stability and inhibited VSMC directional migration and neointima formation. Finally, local transfection of Kat2a siRNA decreased TUBA acetylation and prevented the attenuation of vascular injury-induced neointima formation in ulk1 KO mice. These findings suggest that Ulk1 deletion inhibits neointima formation by reducing autophagic degradation of KAT2A and increasing TUBA acetylation in VSMCs.Abbreviations: ACTA2/α-SMA: actin, alpha 2, smooth muscle, aorta; ACTB: actin beta; ATAT1: alpha tubulin acetyltransferase 1; ATG: autophagy related; BECN1: beclin 1; BP: blood pressure; CAL: carotid artery ligation; CQ: chloroquine diphosphate; EC: endothelial cells; EEL: external elastic layer; FBS: fetal bovine serum; GAPDH: glyceraldehyde 3-phosphate dehydrogenase; HASMCs: human aortic smooth muscle cells; HAT1: histone acetyltransferase 1; HDAC: histone deacetylase; IEL: inner elastic layer; IP: immunoprecipitation; KAT2A/GCN5: K(lysine) acetyltransferase 2A; KAT8/hMOF: lysine acetyltransferase 8; MAP1LC3: microtubule associated protein 1 light chain 3; MYH11: myosin heavy chain 11; PBS: phosphate-buffered saline; PDGF: platelet derived growth factor; PECAM1/CD31: platelet and endothelial cell adhesion molecule 1; RAC3: Rac family small GTPase 3; SIRT2: sirtuin 2; SPP1/OPN: secreted phosphoprotein 1; SQSTM1/p62: sequestosome 1; TAGLN/SM22: transgelin; TUBA: tubulin alpha; ULK1: unc-51 like autophagy activating kinase; VSMC: vascular smooth muscle cell; VVG: Verhoeff Van Gieson; WT: wild type.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia , Neointima , Tubulina (Proteína) , Fatores de Transcrição de p300-CBP , Acetilação , Animais , Autofagia/fisiologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Movimento Celular , Proliferação de Células , Células Cultivadas , Células Endoteliais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos de Músculo Liso/metabolismo , Neointima/metabolismo , Tubulina (Proteína)/metabolismo , Fatores de Transcrição de p300-CBP/metabolismo
19.
Exp Parasitol ; 124(2): 167-71, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19735656

RESUMO

Nifurtimox and benznidazole are the only active drugs against Trypanosoma cruzi; however, they have limited efficacy and severe side effects. During primoinfection, T. cruzi infected macrophages mount an antiparasitic response, which the parasite evades through an increase of tumor growth factor beta and PGE(2) activation as well as decreased iNOS activity. Thus, prostaglandin synthesis inhibition with aspirin might increase macrophage antiparasitic activity and increase nifurtimox and benznidazole effect. Aspirin alone demonstrated a low effect upon macrophage antiparasitic activity. However, isobolographic analysis of the combined effects of aspirin, nifurtimox and benznidazole indicated a synergistic effect on T. cruzi infection of RAW cells, with combinatory indexes of 0.71 and 0.61, respectively. The observed effect of aspirin upon T. cruzi infection was not related with the PGE(2) synthesis inhibition. Nevertheless, NO() levels were restored by aspirin in T. cruzi-infected RAW cells, contributing to macrophage antiparasitic activity improvement. Thus, the synergy of aspirin with nifurtimox and benznidazole is due to the capability of aspirin to increase antiparasitic activity of macrophages.


Assuntos
Aspirina/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Nifurtimox/farmacologia , Nitroimidazóis/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Concentração Inibidora 50 , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Óxido Nítrico/metabolismo
20.
J Med Chem ; 63(5): 2372-2390, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31790581

RESUMO

Neuropathic pain (NP) is a complex chronic pain state with a prevalence of almost 10% in the general population. Pharmacological options for NP are limited and weakly effective, so there is a need to develop more efficacious NP attenuating drugs. Activation of the type 1 lysophosphatidic acid (LPA1) receptor is a crucial factor in the initiation of NP. Hence, it is conceivable that a functional antagonism strategy could lead to NP mitigation. Here we describe a new series of LPA1 agonists among which derivative (S)-17 (UCM-05194) stands out as the most potent and selective LPA1 receptor agonist described so far (Emax = 118%, EC50 = 0.24 µM, KD = 19.6 nM; inactive at autotaxin and LPA2-6 receptors). This compound induces characteristic LPA1-mediated cellular effects and prompts the internalization of the receptor leading to its functional inactivation in primary sensory neurons and to an efficacious attenuation of the pain perception in an in vivo model of NP.


Assuntos
Analgésicos/química , Analgésicos/uso terapêutico , Neuralgia/tratamento farmacológico , Receptores de Ácidos Lisofosfatídicos/agonistas , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Descoberta de Drogas , Feminino , Humanos , Hidrocarbonetos Aromáticos/química , Hidrocarbonetos Aromáticos/uso terapêutico , Camundongos Endogâmicos C57BL , Modelos Moleculares , Neuralgia/metabolismo , Percepção da Dor/efeitos dos fármacos , Ratos Wistar , Receptores de Ácidos Lisofosfatídicos/metabolismo , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo
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