Sample records for kinases
from WorldWideScience.org

Sample records 1 - 6 shown.



1

Sistema colinérgico: revisitando receptores, regulação e a relação com a doença de Alzheimer, esquizofrenia, epilepsia e tabagismo/ Colinergic system: revisiting receptors, regulation and the relationship with Alzheimer disease, schizophrenia, epilepsy and smoking

Ventura, Ana L. M.; Abreu, Paula A.; Freitas, Rodrigo C. C.; Sathler, Plínio C.; Loureiro, Natália; Castro, Helena C.
2010-01-01

Resumo em português OBJETIVO: Revisar a estrutura e o funcionamento do sistema colinérgico central ressaltando seu papel na fisiologia e na fisiopatologia das doenças de Alzheimer e Parkinson, esquizofrenia, epilepsia e tabagismo. MÉTODO: Foi realizada uma pesquisa bibliográfica no MedLine, LILACS, PubMed e ISI, e na Biblioteca da Fundação Oswaldo Cruz, RJ, selecionando-se o período de 1914 a 2009, utilizando os descritores: "receptors", "cholinergic", "Alzheimer disease", "schizophre (mais) nia", "epilepsy" e "smoking", além de referências cruzadas dos artigos selecionados e análise adicional de referências na literatura específica do tema. RESULTADOS: Efeitos importantes da ativação de receptores colinérgicos nicotínicos e muscarínicos sobre o desenvolvimento do sistema nervoso central (SNC) têm sido descritos. A dessensibilização e a internalização dos receptores acoplados à proteína G mediadas pela ativação de proteínas cinases têm sido descritas em proliferação, diferenciação e morte celular, além de síndromes neuropsiquiátricas. CONCLUSÃO: As informações produzidas a partir de estudos do sistema de neurotransmissão colinérgica podem auxiliar no desenvolvimento de medicamentos mais específicos para o tratamento da doença de Alzheimer, esquizofrenia, epilepsia e tabagismo. Resumo em inglês OBJECTIVES: To review articles regarding important topics about cholinergic system and its ionotropic and G-protein coupled receptors as well as their regulation, also enlightening its importance in central nervous system (CNS) development and in several neuropsychiatric conditions such as Alzheimer disease, schizophrenia, epilepsy and smoking. METHOD: Bibliographical research was completed through MedLine, LILACS, PubMed, ISI and the Fundação Oswaldo Cruz Library, RJ, (mais) specifically for 1914 to 2009, using the descritors: "receptors", "cholinergic", Alzheimer "disease", "schizophrenia", "epilepsy" and "smoking", in addition to the cross-reference of the articles selected and further analyses of bibliographical references on the theme. RESULTS: Currently literature describes important effects of nicotinic and muscarinic receptors activation on development of central nervous system (CNS). The protein G coupled receptors dessensibilization and internalization mediated by kinases have been described in proliferation, differentiation and cell death, and also in neurologic disorders. DISCUSSION: The importance of the cholinergic system and its relationship with pathologies such as Alzheimer disease, schizophrenia, epilepsy is evident. The data produced so far may help on planning medicaments more specific for these pathologies treatment.

Scientific Electronic Library Online (Portuguese)

2

Proteínas tirosina fosfatases: propriedades e funções biológicas/ Protein tyrosine phosphatases: properties and biological functions

Aoyama, Hiroshi; Silva, Telma Maria Araújo; Miranda, Márcio André; Ferreira, Carmen Veríssima
2003-12-01

Resumo em inglês Protein phosphorylation-dephosphorylation catalyzed by the opposing and dynamic action of protein kinases and phosphatases probably, is the most crucial chemical reaction taking place in living organisms. Protein phosphatases are classified according to their substrate specificity and sensitivity to inhibitory or activator agents, into two families of protein phosphatases: serine/threonine phosphatases and tyrosine phosphatases (PTPs). PTPs can be divided into 3 groups: t (mais) yrosine specific phosphatases, dual and low molecular weight phosphatases. The role of tyrosine phosphorylation in mitogenic signaling is well documented, and one would predict that vanadate, pervanadate and other oxidant agents (protein tyrosine phosphatase inhibitors) may act as a growth stimulator.

Scientific Electronic Library Online (Portuguese)

3

Proteínas quinases: características estruturais e inibidores químicos/ Kinase protein: structural features and chemical inhibitors

Silva, Bárbara V.; Horta, Bruno A. C.; Alencastro, Ricardo Bicca de; Pinto, Angelo C.
2009-01-01

Resumo em inglês Protein kinases are one of the largest protein families and they are responsible for regulation of a great number of signal transduction pathways in cells, through the phosphorylation of serine, threonine, or tyrosine residues. Deregulation of these enzymes is associated with several diseases including cancer, diabetes and inflammation. For this reason, specific inhibition of tyrosine or serine/threonine kinases may represent an interesting therapeutic approach. The most (mais) important types of protein kinases, their structural features and chemical inhibitors are discussed in this paper. Emphasis is given to the small-molecule drugs that target the ATP-binding sites of these enzymes.

Scientific Electronic Library Online (Portuguese)

4

Neurotrofinas na epilepsia do lobo temporal/ Neurotrophins in temporal lobe epilepsy

Kandratavicius, Ludmyla; Monteiro, Mariana Raquel; Silva, Raquel Araujo do Val-da; Leite, João Pereira
2010-01-01

Resumo em português INTRODUÇÃO: A neurotrofinas NGF, BDNF, NT-3 e NT-4 são os principais representantes da família das neurotrofinas no sistema nervoso central de mamíferos. Estão presentes em estágios específicos do crescimento e sobrevivência neuronal como a divisão celular, diferenciação e axogênese e também nos processos naturais de morte celular neuronal. A atividade biológica das neurotrofinas é mediada pelos receptores de tropomiosina quinase Trk. NGF ativa principalme (mais) nte os receptores TrkA, BDNF e NT-4 interagem com os receptores TrkB e NT-3 com TrkC. Todas as NTs também podem se ligar, com menor afinidade, ao receptor p75NTR. Nesta breve revisão serão levantadas as principais evidências sobre o papel e expressão das principais neurotrofinas no hipocampo, com ênfase nas alterações que ocorrem em modelos animais de epilepsia. RESULTADOS: As neurotrofinas parecem ter um papel chave na plasticidade sináptica relacionada à epilepsia, onde elas poderiam agir tanto como fatores promotores da epileptogênese quanto como substâncias anti-epiléptogênicas endógenas. Além disso a expressão dos genes que codificam os fatores neurotróficos e seus receptores pode ser alterada pela atividade de crises em diversos modelos de epilepsia. CONCLUSÃO: Vários estudos têm demonstrado a relação entre a expressão das neurotrofinas e as alterações na plasticidade dos circuitos neuronais que ocorrem após danos cerebrais, tais como a epilepsia. O conhecimento das alterações na expressão das neurotrofinas na plasticidade neuronal pode nos auxiliar a entender como estas moléculas participam dos mecanismos epileptogênicos e dessa forma, dar início ao estudo de novas terapias e ao desenvolvimento de novas drogas que auxiliem no tratamento da epilepsia. Resumo em inglês INTRODUCTION: NGF, BDNF, NT-3 and NT-4 are the major neurotrophins in the mammal central nervous system. These proteins play key roles in development of the nervous system, but they are also responsible for important functions in the adult brain, such as trophic support of adult neurons, cell plasticity and death. The neurotrophins activate three different members of the tropomyosin-related kinase (Trk) family of receptor tyrosine kinases. These three receptors exhibit di (mais) stinct affinities for different neurotrophins, with NGF activating TrkA, BDNF and NT-4 activating TrkB, and NT-3 predominantly activating TrkC. All NTs can also interact with the receptor p75NTR, a member of the tumor necrosis factor receptor superfamily. RESULTS: NTs have a key role also in the neuronal plasticity related to epilepsy, and they are able to act as epileptogenic factors and anti-epileptogenic endogenous factors. Besides that, several studies have shown that status epilepticus and chronic seizures may alter gene and protein expression of these factors. CONCLUSION: Here, we briefly give a short review of current knowledge of the roles and expression of the major neurotrophins in the hippocampus, with emphasis to the changes that occur in animal models of epilepsy. The knowledge on how the mechanisms underlying the multiplicity of biological functions in which the neurotrophins take part may provide us key insights into the cellular mechanisms of neuronal function in health and disease.

Scientific Electronic Library Online (Portuguese)

5

A cascata dos fosfoinositídeos/ The phosphoinositide cascate

Almeida, Mauro Vieira de; Silva, Adilson David da; Souza, Marcus Vinícius Nora de; Benício, Aloísio Antônio Alves
2003-01-01

Resumo em inglês Inositol is a polyalcohol required for the proper formation of cell membranes. In the body, its plays an important role in the transmission of nerve impulses, its also helps in the transporting of fats within the body. In mammals, inositol exists as phosphorylated derivatives, various phosphoinositides, and in its free form. Agonist stimulated hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is the first step in the transmembrane signalling mechanism when c (mais) ells respond to external stimuli. Under control of activated phospholipase C (PLC) via G-protein, two second messengers D-myo-inositol 1,4,5-triphosphate [Ins(1,4,5)P3] and diacylglycerol are released into the cell. From Ins(1,4,5)P3, enzymatic process under phosphatases or kinases control affords subsequent inositol phosphate metabolites. During the last decade the synthesis of modified inositol phosphate derivatives has been strongly investigated. This paper reviews principal aspects about synthesis and biological functions of these biomolecules.

Scientific Electronic Library Online (Portuguese)

6

A biologia molecular no prognóstico do carcinoma da tireóide/ Molecular biology in the prognosis of thyroid carcinoma

Rodrigues, Aluizio Soares de Souza
2003-12-01

Resumo em inglês This overview examines some selected genetic mechanisms of cancer development. Strong evidence has been accumulated suggesting that alteration in either the struture or activity of proto-oncogene contributes to the development and for the maintenance of the malignant phenotype. Many factors are known to interfere with both normal and pathological controls of growth and differentiation of thyroid cells. Among them, some are oncogenes, like those encoding g-proteins (ras, g (mais) sp, TSH-R), encoding thyrosino kinases receptors (RET, trk, c-met, c-erb, BRAF) and encoding nuclear proteins (c-myc, e-fós). Others are anti-oncogenes (p53, p15, RB), by loss of the growth suppression ativity of the suppressive gene. Cancer cell invasion and metastasis are the major causes of morbidity and mortality in cancer patients. Many genes are involved in the mechanism of invasion and metastasis of thyroid tumors, like Nis, b-catenina, E-caderina, galectina-3, GLUT, telomerase, VEGT, nm-23. All these oncogenes, antioncogenes and tumor invasion and metastasis-related genes are analysed. Several clinical and prognostic factors have been proposed to identify patients at risk for the development of metastasis and death. The role of molecular genetics in this issue is discussed. However, other studies are needed to validate molecular alterations as an independent prognostic factor in thyroid cancer.

Scientific Electronic Library Online (Portuguese)