Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia

Detalhes bibliográficos
Autor(a) principal: Marques Lemos, Ana Rita
Data de Publicação: 2015
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10400.18/3702
Resumo: Dissertação de Mestrado em Genética Molecular e Biomedicina, apresentado à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2015. Defendida e aprovada em 18 de novembro de 2015.
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spelling Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemiaHipercolesterolémiaDoença CardiovascularHomocisteinilação de ProteínasParaoxonase-1Actividade LactonaseDoenças Cardio e Cérebro-vascularesHypercholesterolemiaCardiovascular DiseaseProtein HomocysteinylationParaoxonase-1Lactonase ActivityDissertação de Mestrado em Genética Molecular e Biomedicina, apresentado à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2015. Defendida e aprovada em 18 de novembro de 2015.Trabalho de investigação realizado em colaboração com Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis do Instituto Nacional de Saúde Doutor Ricardo Jorge, Grupo de Investigação Cardiovascular (Setembro 2014 – Setembro 2015).Co-orientadora Mafalda Bourbon: Departamento de Promoção da Saúde e Prevenção de Doenças não Transmissíveis, do Instituto Nacional de Saúde Doutor Ricardo Jorge.[PT] As doenças cardiovasculares (DCVs) são uma das principais causas de morte mundialmente e um dos factores que esta na sua origem e a hipercolesterolémia. A hipercolesterolémia pode ter uma base genética (hipercolesterolémia familiar, HF) e não genética (hipercolesterolémia clinica, HC), sendo a primeira muito mais severa, originando aterosclerose prematura. Se por um lado a função patofisiológica da homocisteína (Hcy) na DCV e ainda controversa, por outro, a S e N-homocisteinilacão de proteínas oferece um novo paradigma a ser considerado na patogénese vascular da hipercolesterolémia. Neste sentido, o presente estudo ambiciona revelar novos conceitos sobre a ligação de Hcy a proteínas, na HC e HF. Foram incluídos no estudo 187 indivíduos: 65 normolipidémicos e 122 hipercolesterolémicos. As fraccões de Hcy total (tHcy) e livre (fHcy) foram quantificadas em amostras de soro apos validação de um método de HPLC-FD, para avaliar a S-homocisteinilacão. A actividade de lactonase (LACase) da enzima paraoxonase-1 (PON1) foi quantificada por um ensaio colorimétrico para avaliar a N-homocisteinilacão. Os níveis de tHcy não diferem entre grupos. Não obstante, a fraccão fHcy diminui nos grupos hipercolesterolémicos, com maior evidencia para a população HF. Consequentemente, parece haver um aumento de S-homocisteinilacão, independentemente da terapia de redução lipídica (TRL). Também a actividade LACase e mais baixa neste grupo, mesmo com TRL, por isso, o risco de Nhomocisteinilacão parece ser maior. Alem disso, a diminuição dos rácios LACase/ApoA1 e LACase/HDL na população HF mostra que a lipoproteína de alta densidade (HDL) esta disfuncional nesta população apesar da concentração ser normal. Os resultados suportam a hipótese de que a função patofisiológica da Hcy na Hipercolesterolemia pode residir na sua capacidade de fazer modificações pos-traducionais em proteínas. Este fenómeno e particularmente evidente na condição de HF. No futuro será interessante identificar quais as proteínas-alvo envolvidas na progressão da patologia vascular. ABSTRACT - Cardiovascular diseases (CVDs) are one of the leading causes of death and disability worldwide and one of its underlying causes is hypercholesterolemia. Hypercholesterolemia can have genetic (familial hypercholesterolemia, FH) and non-genetic causes (clinical hypercholesterolemia, CH), the first much more severe, with occurrence of premature atherosclerosis. While the pathophysiological role of homocysteine (Hcy) on CVD is still controversial, molecular targeting of protein by S and N-homocysteinylation offers a new paradigm to be considered in the vascular pathogenesis of hypercholesterolemia. On this regard, the present study aims to give new insights on protein targeting by Hcy in both CH and FH conditions. A total of 187 subjects were included: 65 normolipidemic and 122 hypercholesterolemic. Total (tHcy) and free (fHcy) fractions were quantified in serum samples after validation of an HPLCFD method, to assess S-homocysteinylation. Also, the lactonase (LACase) activity of paraoxonase-1 (PON1) was quantified by a colorimetric assay, as a surrogate of N-homocysteinylation. tHcy does not differ among groups. Nevertheless, fHcy declines in the hypercholesterolemic groups, with more evidence to the FH population. Consequently, there seems to be an increase of Shomocysteinylation, regardless of lipid lowering therapy (LLT). Also, despite of LLT use, LACase activity is lower in FH, thus the risk for protein N-homocysteinylation seems to be higher. Moreover, the decrease in LACase/ApoA1 and LACase/HDL ratios in FH, shows that HDL is dysfunctional in this population, despite its normal concentration values. Data supports that the pathophysiological role of Hcy on hypercholesterolemia may reside in its ability to post-translationally modify proteins. This role is particularly evident in FH condition. In the future, it will be interesting to identify which target proteins are modified and thus involved in vascular pathology progression. Cardiovascular diseases (CVDs) are one of the leading causes of death and disability worldwide and one of its underlying causes is hypercholesterolemia. Hypercholesterolemia can have genetic (familial hypercholesterolemia, FH) and non-genetic causes (clinical hypercholesterolemia, CH), the first much more severe, with occurrence of premature atherosclerosis. While the pathophysiological role of homocysteine (Hcy) on CVD is still controversial, molecular targeting of protein by S and N-homocysteinylation offers a new paradigm to be considered in the vascular pathogenesis of hypercholesterolemia. On this regard, the present study aims to give new insights on protein targeting by Hcy in both CH and FH conditions. A total of 187 subjects were included: 65 normolipidemic and 122 hypercholesterolemic. Total (tHcy) and free (fHcy) fractions were quantified in serum samples after validation of an HPLCFD method, to assess S-homocysteinylation. Also, the lactonase (LACase) activity of paraoxonase-1 (PON1) was quantified by a colorimetric assay, as a surrogate of N-homocysteinylation. tHcy does not differ among groups. Nevertheless, fHcy declines in the hypercholesterolemic groups, with more evidence to the FH population. Consequently, there seems to be an increase of Shomocysteinylation, regardless of lipid lowering therapy (LLT). Also, despite of LLT use, LACase activity is lower in FH, thus the risk for protein N-homocysteinylation seems to be higher. Moreover, the decrease in LACase/ApoA1 and LACase/HDL ratios in FH, shows that HDL is dysfunctional in this population, despite its normal concentration values. Data supports that the pathophysiological role of Hcy on hypercholesterolemia may reside in its ability to post-translationally modify proteins. This role is particularly evident in FH condition. In the future, it will be interesting to identify which target proteins are modified and thus involved in vascular pathology progression.[EN] Cardiovascular diseases (CVDs) are one of the leading causes of death and disability worldwide and one of its underlying causes is hypercholesterolemia. Hypercholesterolemia can have genetic (familial hypercholesterolemia, FH) and non-genetic causes (clinical hypercholesterolemia, CH), the first much more severe, with occurrence of premature atherosclerosis. While the pathophysiological role of homocysteine (Hcy) on CVD is still controversial, molecular targeting of protein by S and N-homocysteinylation offers a new paradigm to be considered in the vascular pathogenesis of hypercholesterolemia. On this regard, the present study aims to give new insights on protein targeting by Hcy in both CH and FH conditions. A total of 187 subjects were included: 65 normolipidemic and 122 hypercholesterolemic. Total (tHcy) and free (fHcy) fractions were quantified in serum samples after validation of an HPLCFD method, to assess S-homocysteinylation. Also, the lactonase (LACase) activity of paraoxonase-1 (PON1) was quantified by a colorimetric assay, as a surrogate of N-homocysteinylation. tHcy does not differ among groups. Nevertheless, fHcy declines in the hypercholesterolemic groups, with more evidence to the FH population. Consequently, there seems to be an increase of Shomocysteinylation, regardless of lipid lowering therapy (LLT). Also, despite of LLT use, LACase activity is lower in FH, thus the risk for protein N-homocysteinylation seems to be higher. Moreover, the decrease in LACase/ApoA1 and LACase/HDL ratios in FH, shows that HDL is dysfunctional in this population, despite its normal concentration values. Data supports that the pathophysiological role of Hcy on hypercholesterolemia may reside in its ability to post-translationally modify proteins. This role is particularly evident in FH condition. In the future, it will be interesting to identify which target proteins are modified and thus involved in vascular pathology progression.Pereira, SofiaBourbon, MafaldaRepositório Científico do Instituto Nacional de SaúdeMarques Lemos, Ana Rita2016-03-22T15:18:39Z2015-11-182015-11-18T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10400.18/3702enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-20T15:39:58Zoai:repositorio.insa.pt:10400.18/3702Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T18:38:36.452355Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
title Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
spellingShingle Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
Marques Lemos, Ana Rita
Hipercolesterolémia
Doença Cardiovascular
Homocisteinilação de Proteínas
Paraoxonase-1
Actividade Lactonase
Doenças Cardio e Cérebro-vasculares
Hypercholesterolemia
Cardiovascular Disease
Protein Homocysteinylation
Paraoxonase-1
Lactonase Activity
title_short Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
title_full Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
title_fullStr Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
title_full_unstemmed Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
title_sort Molecular targeting of proteins by homocysteine: implications in familial and clinical hypercholesterolemia
author Marques Lemos, Ana Rita
author_facet Marques Lemos, Ana Rita
author_role author
dc.contributor.none.fl_str_mv Pereira, Sofia
Bourbon, Mafalda
Repositório Científico do Instituto Nacional de Saúde
dc.contributor.author.fl_str_mv Marques Lemos, Ana Rita
dc.subject.por.fl_str_mv Hipercolesterolémia
Doença Cardiovascular
Homocisteinilação de Proteínas
Paraoxonase-1
Actividade Lactonase
Doenças Cardio e Cérebro-vasculares
Hypercholesterolemia
Cardiovascular Disease
Protein Homocysteinylation
Paraoxonase-1
Lactonase Activity
topic Hipercolesterolémia
Doença Cardiovascular
Homocisteinilação de Proteínas
Paraoxonase-1
Actividade Lactonase
Doenças Cardio e Cérebro-vasculares
Hypercholesterolemia
Cardiovascular Disease
Protein Homocysteinylation
Paraoxonase-1
Lactonase Activity
description Dissertação de Mestrado em Genética Molecular e Biomedicina, apresentado à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2015. Defendida e aprovada em 18 de novembro de 2015.
publishDate 2015
dc.date.none.fl_str_mv 2015-11-18
2015-11-18T00:00:00Z
2016-03-22T15:18:39Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10400.18/3702
url http://hdl.handle.net/10400.18/3702
dc.language.iso.fl_str_mv eng
language eng
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eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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