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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
751

Diversity in competitive ligand-receptor interactions : electrophysiological studies of ligand-receptor interactions at native and recombinant GABAA receptors /

Vestergaard, Henrik Tang. January 2003 (has links)
Ph D.
752

THE ROLE OF ATP AND FK-506 BINDING PROTEIN IN THE COUPLED GATING OF SKELETAL RYANODINE RECEPTORS

Neumann, Jacob Trevor 01 May 2011 (has links)
During skeletal muscle stimulation, there is a summation of local events of Ca2+ release from the sarcoplasmic reticulum, known as Ca2+ sparks. Ca2+ sparks originate from groups of skeletal ryanodine receptors (RyR1) that activate and close in synchrony. This synchrony allows for the rapid and massive release of Ca2+ from the sarcoplasmic reticulum to initiate contraction and, more important, would provide a mechanism to terminate Ca2+ release under conditions where independent RyR1 are normally active. RyR1 mutations can result in abnormal intracellular Ca2+ signaling that is associated with numerous skeletal muscle disorders including malignant hyperthermia and central core disease. Therefore, investigating the mechanisms that control RyR1 function can help identify how these mutations cause deleterious Ca2+ handling. Currently, most published research on RyR1s gating utilizes single RyR1 reconstituted into planar lipid bilayers to test isolated RyR1. However, in vivo, arrays of RyR1 function in synchrony. Attempts to reconstitute RyR1s into planar lipid bilayers result in experiments that contain multiple channels, which under specific conditions may gate in synchrony, also known as coupled gating. Coupled RyR1 gating was first reported by A. Marks' laboratory and attributed to FK-506 binding protein 12 (FKBP12) associating with neighboring RyR1s the stabilization of RyR1-RyR1 interactions that promote coupled gating. Previous studies suggested that ATP is required for coupled RyR1 gating; however, the mechanism by which ATP promotes the coordinated activity of RyR1s has not been elucidated and is the focus of this thesis. Therefore, my hypothesis is that the agonist action of ATP and FKBP12 bound to RyR1 are required for coupled RyR1 gating. In addition, new pharmacological tools are required to better understand coupled RyR gating. Thus, an additional goal is to identify pharmacological agents that modulate RyR1s in an innovative manner, i.e., help to uncover novel aspects of RyR1 gating and conduction. This investigation suggests that the adenosine based nucleotides, ATP, ADP and AMP, are agonists of RyR1s and promote coupled RyR1 gating in planar lipid bilayers. However, ADP and AMP were unable to maintain coupled RyR1 gating with physiological levels of Mg2+. This suggests that coupled gating would be impaired when the levels ATP decrease, as in muscle fatigue. When ATP was compared to other nucleotides (GTP, ITP, and TTP), the results suggest that the nucleotide agonist action on RyR1s is dependent on the phosphate groups and amino group on the nucleobase. As ATP is the most efficient nucleotide for coupled gating, I also investigated the indirect action of ATP to act as a kinase substrate or alter the cytoskeletal network. The addition of kinases, phosphatases and cytoskeletal modulators did not produce a significant disruption of coupled RyR1 gating. I also tested the role of addition of exogenous FKBP12 to RyR1s that gated independently or had partial coupling, but coupled gating was never improved. Also, the addition of high doses of rapamycin to remove FKBP12 from coupled RyR1 failed to functionally uncouple the channels. Finally, I attempted to find pharmacological agents that could aid in the understanding of coupled RyR1. Some agents were found to modulate RyR1s; however, I did not find a probe that would affect kinetics/conductance of RyR1s and was suitable for comparing coupled gating in bilayers with Ca2+ sparks in cells. Overall, coupled RyR gating is dependent on the physiological modulators ATP and Mg2+. This thesis represents a step forward in identifying the requirements for coupled RyR1 gating and understanding how RyR1s function in cells. Until an understanding of how these receptors communicate in cells is obtained, how different mutations alter the Ca2+ leak will continue to be quite difficult to study.
753

Modulation of NMDA receptor surface expression by DISC1 and its pathway partners

Crummie, Darragh Kevin January 2015 (has links)
Disrupted in Schizophrenia 1 (DISC1) is a well supported risk factor for schizophrenia, bipolar disorder and major recurrent depression. DISC1 is a multifunctional multicompartmentalised scaffold protein with essential roles in neuronal proliferation, differentiation, migration and integration. DISC1 also modulates pathways of vital importance for neuronal signalling and plasticity. One of the major hypotheses for the cause of psychiatric illness is N-methyl-D-aspartate (NMDA) receptor hypofunction. It was observed that NMDA receptor antagonists can induce symptoms of schizophrenia in unaffected individuals, and exacerbate symptoms in patients with schizophrenia. Recent work in our laboratory showed that DISC1 complexes with NMDA receptors within the cell body and at synapse of neurons. Here I studied whether DISC1, or DISC1 missense variants, affect the trafficking of NMDA receptors. This was done by quantifying surface NMDA receptor expression in the presence of DISC1 or variant DISC1. I found that one common variant, 607F, causes a significant reduction in surface expressed NMDA receptors. I went on to show that DISC1 reduces the number of internalised receptors associating with early RAB5-containing endosomes. This indicates that DISC1 may be involved in the trafficking and recycling of NMDA receptors, a process that may be affected by the missense DISC1 variant 607F. Further to this I studied the effects on NMDA receptor trafficking of DISC1 pathway partners Nuclear Distribution Element 1 (NDE1) and Trafficking-protein kinesin binding 1 (TRAK1), both regulators of neuronal intracellular trafficking. Phosphorylation of NDE1 at T131 has been shown to be modulated by DISC1. Using phospho-mimic and phospho-dead NDE1 expression constructs I observed a significant reduction in the surface-expressed NMDA receptors in cells expressing the phospho-mimic form of NDE1. NDE1 may therefore be involved in the trafficking of NMDA receptors, and this role may be modulated by phosphorylation of NDE1. Finally, TRAK1 was shown to associate robustly with the GluN2B subunit, and to decrease the surface expression of NMDA receptors, most likely by sequestering them. The TRAK1-induced GluN2B sequestration may be an artefact, but the association of the trafficking molecule TRAK1 with this subunit may point towards a role in NMDA receptor trafficking. These proteins have been shown to associate with each other and may form a complex in order to traffic NMDA receptors. Disruption of this complex by defective DISC1 expression may affect NMDA receptor trafficking. In the brain this could conceivably contribute to NMDA receptor hypofunction and the development of psychiatric illness.
754

MODULATION OF SYNAPTIC TRANSMISSION AT THE NUCLEUS TRACTUS SOLITARIUS

FENG, LIN 01 May 2014 (has links)
The caudal nucleus tractus solitarius (cNTS) is the key recipient of the primary afferents from visceral sensory neurons and also an important site that processes and integrates gastrointestinal, cardiovascular and respiratory functions. Glutamate and gamma-aminobutyric acid are the major neurotransmitters within the NTS, but studies have suggested that nicotinic acetylcholine receptors (nAChRs) and transient receptor potential (TRP) channels can modulate excitatory/inhibitory neurotransmission. I have designed studies to understand the role of nAChRs and TRP channels in the modulation of neurotransmission in the cNTS. In the first aim, experiments were designed to test the hypothesis that the cNTS contains function-specific subsets of neurons whose responsiveness to nicotine correlates with the target of their axonal projections. cNTS neurons send axonal projections to brain regions such as parabrachial nucleus (PBN), hypothalamic paraventricular nucleus (PVN), nucleus ambiguous (NA), dorsal motor nucleus of the vagus (DMV) and the caudal ventrolateral medulla (CVLM) and are involved in integrating autonomic and neuroendocrine functions. Presynaptic/postsynaptic modulation by nAChRs differ in the axonal projections of cNTS neurons, studying of which would provide better understanding of this complex integration. In vivo fluorescent tracing combined with in vitro slice patch-clamp electrophysiological recordings from anatomically identified caudal NTS neurons were used to study the expression and function of nAChRs (mainly á3â4 containing nAChRs) in the cNTS. Results from these studies demonstrate that presynaptic and postsynaptic responsiveness of caudal NTS neurons to nicotine correlates with the areas the neurons project to in the following order of prevalence: DMV>PVN>NA>CVLM>PBN (for presynaptic responses) and DMV>CVLM>PBN>NA>PVN (for postsynaptic responses). In the second aim, experiments were designed to test the hypothesis that nociceptive TRP channels TRPV1 (vanilloid) and TRPA1 (ankyrin) modulate synaptic transmission in the NTS. As a result of this modulation, the efferent functions that control autonomic and visceral functions will be regulated and account for the changes in autonomic neuropathy as patients with diabetes develop significant alterations in blood pressure and heart rate as well as silent myocardial ischemia as a result of blunted pain carrying ability. Results obtained from these studies demonstrated that TRPV1 and TRPA1 mRNA were detected in the dorsal root ganglion (DRG), but not in the NTS. Immunofluorescence studies revealed that TRPV1 and TRPA1 were expressed in the solitary tract central sensory terminals inputs to NTS but not in NTS neurons. This suggests that TRPV1 and TRPA1 are expressed only in solitary tract. Administration of capsaicin (TRPV1 agonist) and allyl isothiocyanate (AITC, TRPA1 agonist) both increased the frequency of s/mEPSCs without affecting spontaneous and miniature inhibitory postsynaptic currents (s/mIPSCs). Next, the modulation of TRPV1- and TRPA1-induced responses by utilizing a PKC activator (PDBu) was examined. Incubation of slices with PDBu synergistically increased the mEPSC frequency following capsaicin application suggesting an increased receptor affinity; however following application of AITC there was no significant change, suggesting that activation by covalent modification does not enhance binding affinity. Finally, the specificity of TRPV1 and TRPA1 effect on synaptic transmission by ablating TRPV1 and TRPA1were tested. There was no modulation of synaptic transmission in these animals, further confirming that capsaicin- and AITC-mediated modulation of synaptic transmission are specifically mediated by TRPV1 and TRPA1, respectively. Furthermore, animals with painful diabetic peripheral neuropthy exhibited enhanced synaptic activity at the NTS, suggesting a role in nociception and other visceral functions. In summary, nAChRs, TRPV1 and TRPA1 are expressed in the NTS and activation of which modulate excitatory synaptic transmission. The results obtained from these studies and their interpretation may provide a better understanding of the central mechanism of modulation on efferent functions from NTS that regulate cardiovascular, respiratory and gastrointestinal functions.
755

Immunohistochemical Localization of Prolactin Receptors Within the Equine Ovary

Oberhaus, Erin Lea 01 August 2012 (has links)
Prolactin receptors (PRLr) were detected in anestrous (n=3), winter cycling (n=2), follicular (n=3) and luteal phase (n=3) equine ovaries by IHC. Follicle stages evaluated were primordial, preantral and antral. Receptors were detected in all follicle stages and in CL. PRLr staining was not different (P > 0.05) between primordial and preantral, but was greater (P < 0.001) in antral follicles. Primordial follicles stained weakest in anestrous and follicular phase ovaries, followed by luteal phase ovaries and was most intense in winter cycling. Staining in preantral follicles was weakest in anestrus, followed by follicular phase and highest in winter cycling and luteal phase. Staining was most intense in antral follicles with no difference (P > 0.05) between any of the reproductive states. Oocytes and ovulation fossa also possessed PRLr. In conclusion, concentrations of PRLr are highest in large, antral follicles suggesting a mechanistic role for PRL around the time of ovulation.
756

Investigação do envolvimento de subtipos de adrenoceptores α1 no efeito anti-imobilidade da imipramina no teste de suspensão pela cauda

Ribeiro, Carlos Alberto da Silva [UNESP] 27 February 2015 (has links) (PDF)
Made available in DSpace on 2015-05-14T16:53:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-27Bitstream added on 2015-05-14T16:59:01Z : No. of bitstreams: 1 000828052_20150610.pdf: 305956 bytes, checksum: 7369e2c8e287bd85ed19449e6cb2b2e6 (MD5) Bitstreams deleted on 2015-06-12T11:19:08Z: 000828052_20150610.pdf,. Added 1 bitstream(s) on 2015-06-12T11:19:39Z : No. of bitstreams: 1 000828052.pdf: 458163 bytes, checksum: 8f3277eff5562c7da6c209cf3706a1c0 (MD5) / A imipramina é antidepressivo tricíclico cujo principal mecanismo é a inibição da captura neuronal de noradrenalina e/ou serotonina, aumentando os níveis sinápticos dessas monoaminas. Além disso, a imipramina, bem como outros antidepressivos tricíclicos, antagonizam os adrenoceptores α1 na mesma faixa de concentração em que inibem o transportador de noradrenalina. Por outro lado, estudos recentes mostraram que a imipramina tem afinidades distintas para os três subtipos de adrenoceptores α1, (α1A, α1B e α1D), ou seja, aproximadamente 25 vezes mais seletiva para α1A em relação aos adrenoceptores α1B e 10 vezes para adrenoceptores α1D em relação aos adrenoceptores α1B. Isso sugere que seu mecanismo de ação possa estar relacionado com essa característica, uma vez que, ao aumentar os níveis sinápticos de noradrenalina, antagoniza α1A e α1D, mas deixa relativamente livre α1B. Então, o objetivo desta tese foi investigar a participação dos adrenoceptores α1A, α1B e α1D no efeito anti-imobilidade da imipramina no teste de suspensão pela cauda em camundongos. Para isso, camundongos foram submetidos ao teste de suspensão pela cauda, com a administração de diversos antagonistas seletivos e não-seletivos para subtipos α1. Os testes foram realizados utilizando a imipramina associada ao prazosin, antagonista não-seletivo para adrenoceptores α1, RS-100329, antagonista seletivo pra α1A, L-765314, seletivo par α1B e BMY-7378, seletivo para α1D. Os animais também foram avaliados com administrações únicas dos antagonistas. Esta tese mostrou que a administração concomitante de prazosin ou o L-765314 reverteram o efeito anti-imobilidade da imipramina. Por outro lado, nem o RS-100329 ou BMY-7378 modificaram o efeito anti-imobilidade da imipramina. Além disso, a administração de apenas o RS-100329 ou BMY-7378 apresentou efeito anti-imobilidade no teste de suspensão pela cauda. Isso indica que o efeito ... / Imipramine is a tricyclic antidepressant inhibitor of norepinephrine and serotonin neuronal reuptake. In addition, the imipramine antagonizes α1-adrenoceptors in the same concentration range that inhibited norepinephrine transporter. However, the imipramine has different affinity to α1-adrenoceptor subtypes presenting higher affinity (10-25-fold) towards α1A- and α1D-adrenoceptors compared to α1B-adrenoceptors. This study investigates the α1-adrenoceptor subtypes involved in the anti-immobility effect of imipramine in the tail suspension test in mice. The anti-immobility effect of imipramine was significantly antagonized by the non-subtype-selective α1-adrenoceptor antagonist prazosin. Neither the selective α1A adrenoceptor antagonist RS-100329 nor the selective α1D-adrenoceptor antagonist BMY-7378 changed the anti-immobility effect of imipramine. However, the selective α1B-adrenoceptor antagonist L-765314 antagonized the anti-immobility effect of imipramine. In addition, mice treated only with RS-100329 or BMY-7378 showed reduced immobility time in comparison to mice treated with vehicle, whereas L-765314 increased the immobility time. These results suggests that the α1B-subtype is the main target for the increased levels of norepinephrine caused by imipramine, and that the selective antagonism of α1A- and α1D-adrenoceptors results in anti-immobility effects
757

Characterisation of the C-type lectin receptor Clecsf8

Kerscher, Berhard Gerhard Richard January 2016 (has links)
C-type lectin-like receptors (CTLRs) play critical roles in immunity and homeostasis by recognising a variety of microbial or endogenous ligands. Clecsf8 is a member of the Dectin-2 family of CTLRs. Clecsf8 shares important similarities with its relatives Mincle and Dectin-2, such as the lack of an integral signalling motif and a single, calcium dependent ligand binding domain. They were shown to associate with the FcRγ adaptor, which is essential for receptor surface expression and downstream signalling. Recent publications revealed an important role for Clecsf8 in anti-mycobacterial immunity. It was reported to recognise the mycobacterial cord factor (TDM), similar to the related CTLR Mincle, as well as a possible role in candidiasis. In this study, we characterised the underlying mechanism of Clecsf8 expression in a context of mycobacterial disease. The generation of novel anti-Clecsf8 monoclonal antibodies allowed us to characterise the expression of Clecsf8 in detail in homeostasis and inflammation in murine models in vivo and culture systems in vitro. We found Clecsf8 to be predominantly expressed on monocytes/macrophages and neutrophils within e. g. the peritoneal cavity, blood and bone marrow. Notably, Clecsf8 was expressed only weakly in the lung, but strongly upregulated in a pulmonary mycobacterial infection model. In vitro, Clecsf8 expression on elicited macrophages was strongly induced upon treatment with microbial stimuli in a Myd88- and Mincle dependent manner. Interestingly, surface expression of Clecsf8 in a murine fibroblast cell line was greatly enhanced by co-transfection of Mincle, but not another related CTLR, Dectin-2. Notably, we confirmed mycobacteria as a ligand of CLECSF8, but found no role for the receptor in Candida immunity. In conclusion, Clecsf8 is a myeloid expressed, mycobacterial receptor, showing significant interdependence with Mincle and is regulated through the Myd88 pathway.
758

An investigation of the role of amygdaloid α-2 adrenoceptors in the kindling of seizures

Pelletier, Marc Roger 06 July 2018 (has links)
It has been reported previously that systemic administration of clonidine, an agonist of α-2 receptors for noradrenaline, significantly retards amygdaloid kindling, by delaying the emergence from partial seizure, Conversely, systemic administration of α-2 antagonists has been reported to facilitate amygdaloid kindling, The experiments I conducted attempted to discover whether α-2 adrenoceptors in the amygdala participated in these effects, I examined the effect of either systemic administration (i,p.) or intraamygdaloid infusions of a variety of noradrenergic drugs on the kindling of seizures with electrical stimulation of the amygdala, Rats received either low-frequency stimulation of the amygdala, to induce rapid kindling, or conventional high-frequency stimulation, Drugs and electrical stimulation were administered once every 48 hrs, I observed a significant retardation of kindling in rats receiving i,p. injections of clonidine (0.1 mg/kg) or unilateral infusions of clonidine in concentrations of [special characters omitted] to [special characters omitted] M, regardless of the stimulation frequency. The prophylactic effect was due to a delay in the progression out of partial seizure. I observed similar effects with infusions of xylazine, also an α-2 adrenoceptor agonist, The effect was specific to the amygdala/pyriform region, because infusions of clonidine dorsal lo the amygdala were without effect. Power spectral analysis of the AD from the stimulated and the contralateral amygdala during the initial occurrence of bilateral AD failed to reveal differences attributable to clonidine, Therefore, clonidine might retard kindling by modifying the propagation of AD from the stimulated amygdala to a midbrain or pontine brainstem area critical, for the expression of generalized seizures. Clonidine had no effect on established generalized seizures, suggesting that it was producing a genuine prophylactic effect against kindling. Unexpectedly, intraamygdaloid infusions of either idazoxan, yohimbine, or SK&F 104856, antagonists of α-2 receptors, failed to accelerate kindling. Simultaneous infusion of idazoxan blocked clonidine’s prophylactic effect, which suggests strongly that this effect was mediated at the α-2 adrenoceptor. Blockade of amygdaloid α-1 adrenoceptors with corynanthine failed to affect kindling. I conclude that the population of α-2 adrenoceptors in the amygdala/pyriform region contributes to the antiepileptogenic effect observed after systemic administration of clonidine and that the facilitation of kindling observed after systemic administration of α-2 antagonists reported previously may have been mediated by the blockade of a population of α -2 adrenoceptors in addition to, or outside of, the amygdala/pyriform region. / Graduate
759

Investigação do envolvimento de subtipos de adrenoceptores α1 no efeito anti-imobilidade da imipramina no teste de suspensão pela cauda /

Ribeiro, Carlos Alberto da Silva. January 2015 (has links)
Orientador: André Sampaio Pupo / Banca: Ana Lúcia Severo Rodrigues / Banca: Ricardo Luiz Nunes de Souza / Banca: Márcia Gallacci / Banca: Leonardo Resstel Barbosa Moraes / Resumo: A imipramina é antidepressivo tricíclico cujo principal mecanismo é a inibição da captura neuronal de noradrenalina e/ou serotonina, aumentando os níveis sinápticos dessas monoaminas. Além disso, a imipramina, bem como outros antidepressivos tricíclicos, antagonizam os adrenoceptores α1 na mesma faixa de concentração em que inibem o transportador de noradrenalina. Por outro lado, estudos recentes mostraram que a imipramina tem afinidades distintas para os três subtipos de adrenoceptores α1, (α1A, α1B e α1D), ou seja, aproximadamente 25 vezes mais seletiva para α1A em relação aos adrenoceptores α1B e 10 vezes para adrenoceptores α1D em relação aos adrenoceptores α1B. Isso sugere que seu mecanismo de ação possa estar relacionado com essa característica, uma vez que, ao aumentar os níveis sinápticos de noradrenalina, antagoniza α1A e α1D, mas deixa relativamente livre α1B. Então, o objetivo desta tese foi investigar a participação dos adrenoceptores α1A, α1B e α1D no efeito anti-imobilidade da imipramina no teste de suspensão pela cauda em camundongos. Para isso, camundongos foram submetidos ao teste de suspensão pela cauda, com a administração de diversos antagonistas seletivos e não-seletivos para subtipos α1. Os testes foram realizados utilizando a imipramina associada ao prazosin, antagonista não-seletivo para adrenoceptores α1, RS-100329, antagonista seletivo pra α1A, L-765314, seletivo par α1B e BMY-7378, seletivo para α1D. Os animais também foram avaliados com administrações únicas dos antagonistas. Esta tese mostrou que a administração concomitante de prazosin ou o L-765314 reverteram o efeito anti-imobilidade da imipramina. Por outro lado, nem o RS-100329 ou BMY-7378 modificaram o efeito anti-imobilidade da imipramina. Além disso, a administração de apenas o RS-100329 ou BMY-7378 apresentou efeito anti-imobilidade no teste de suspensão pela cauda. Isso indica que o efeito ... / Abstract: Imipramine is a tricyclic antidepressant inhibitor of norepinephrine and serotonin neuronal reuptake. In addition, the imipramine antagonizes α1-adrenoceptors in the same concentration range that inhibited norepinephrine transporter. However, the imipramine has different affinity to α1-adrenoceptor subtypes presenting higher affinity (10-25-fold) towards α1A- and α1D-adrenoceptors compared to α1B-adrenoceptors. This study investigates the α1-adrenoceptor subtypes involved in the anti-immobility effect of imipramine in the tail suspension test in mice. The anti-immobility effect of imipramine was significantly antagonized by the non-subtype-selective α1-adrenoceptor antagonist prazosin. Neither the selective α1A adrenoceptor antagonist RS-100329 nor the selective α1D-adrenoceptor antagonist BMY-7378 changed the anti-immobility effect of imipramine. However, the selective α1B-adrenoceptor antagonist L-765314 antagonized the anti-immobility effect of imipramine. In addition, mice treated only with RS-100329 or BMY-7378 showed reduced immobility time in comparison to mice treated with vehicle, whereas L-765314 increased the immobility time. These results suggests that the α1B-subtype is the main target for the increased levels of norepinephrine caused by imipramine, and that the selective antagonism of α1A- and α1D-adrenoceptors results in anti-immobility effects / Doutor
760

Análise e caracterização in silico de polimorfismos de base única dos genes Toll Like Receptor: consequências estruturais e funcionais associadas ao desenvolvimento do câncer

Simões, Carolina da Rocha 20 February 2014 (has links)
Submitted by Isaac Francisco de Souza Dias (isaac.souzadias@ufpe.br) on 2015-05-19T16:34:38Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Carolina da Rocha Simões.pdf: 2694652 bytes, checksum: 6446d4fa347e53fe42ce7e769f745124 (MD5) / Made available in DSpace on 2015-05-19T16:34:38Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Carolina da Rocha Simões.pdf: 2694652 bytes, checksum: 6446d4fa347e53fe42ce7e769f745124 (MD5) Previous issue date: 2014-02-20 / CAPES / O aumento da informação proveniente do sequenciamento de alta performance (NGS), e de projetos como o 1000 genomas e HapMap, permitiram a descoberta de milhões de variações. Entretanto, o maior desafio é a identificação da relação entre o genótipo e o fenótipo, proporcionando informações que possam ajudar a definir os polimorfismos que podem ou não causar doenças. Ferramentas computacionais tem auxiliado na predição das modificações estruturais geradas pelos polimorfismos, e as consequentes alterações funcionais sofridas pelas proteínas. Os receptores Toll Like (TLR) são proteínas do sistema imunológico que estão envolvidas na regulação da inflamação e em alguns casos no desenvolvimento do câncer. O objetivo deste projeto foi analisar, através de ferramentas in silico, os polimorfismos de base única nos genes das TLRs, buscando por polimorfismos que possam estar relacionados com a predisposição ao câncer e com alterações da via de sinalização das TLRs. Foram encontrados 37 genes que estão envolvidos na via de sinalização e podem ser utilizados como marcadores genéticos (biomarcadores) para o diagnóstico e predição das alterações na expressão dos genes relacionados à esta via. Estes genes, se regulados, podem ser utilizados como inibidores. Em relação aos polimorfismos foram coletados no banco de dados dbSNP/NCBI 5.839 SNPs entre os 10 genes das TLRs. Destes, 1.017 variações foram classificadas como missense e analisadas para avaliar as consequências estruturais pela troca dos aminoácidos. Para isso quatro ferramentas preditoras (SIFT, Polyphen, MutationAssessor e SDM) foram utilizadas gerando informações sobre as modificações e associando-as com possíveis danos nas proteínas. Dos polimorfismos analisados 223 foram classificados como danosos baseados na troca de aminoácido e podem causar uma desregulação funcional na proteína. Entre eles está o rs5743708 (TLR2), rs3775291, (TLR3) e rs11466653 (TLR10) que já foi estudado in vitro e tiveram associação com câncer colorectal (TLR2 e 3) e carcinoma da tireóide (TLR10). A predição prévia, in silico, das alterações funcionais pode auxiliar na interpretação das variações gênicas, neste caso associadas com o câncer, e também na caracterização precisa dos fatores que levam a estas alterações, contribuindo no diagnóstico, na prevenção e em melhores respostas aos tratamentos oferecidos.

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