Spelling suggestions: "subject:"plasminogen activator inhibitor 1."" "subject:"plasminogens activator inhibitor 1.""
11 |
Relative hypercoagulation induced by suppressed fibrinolysis after tisagenlecleucel infusion in malignant lymphoma / 悪性リンパ腫に対するチサゲンレクルユーセル投与後に見られる線溶抑制および相対的凝固亢進状態Yamasaki(Morita), Makiko 24 November 2022 (has links)
京都大学 / 新制・課程博士 / 博士(人間健康科学) / 甲第24292号 / 人健博第107号 / 新制||人健||8(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 藤井 康友, 教授 岡 昌吾, 教授 滝田 順子 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM
|
12 |
Aspects of Non-Neuronal Signalling Functions of Acetylcholine in Colorectal Cancer : Roles for the α7nAChRNovotny, Ann January 2009 (has links)
No description available.
|
13 |
Hypoxic Regulation of VEGF and PAI-1 Expression by HIF-1[alpha] and HIF-2[alpha] in First Trimester TrophoblastsMeade, Eliza 15 November 2006 (has links)
Preeclampsia results from incomplete trophoblast invasion of the spiral arteries during early pregnancy. Vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) are critical factors involved in angiogenesis, invasion and hemostasis at the maternal-fetal interface. Both factors are transcriptionally regulated by hypoxia inducible factor (HIF), a heterodimeric complex consisting of HIF-1[beta] and either HIF-1[alpha] or -2[alpha] whose specificity or redundancy in gene regulation is cell-type specific. This study uses siRNA technology to dissect the mechanisms of hypoxia-mediated regulation of PAI-1 and VEGF expression in first trimester trophoblasts. Immortalized first trimester human extravillous trophoblasts (HTR8/SVneo cells) were maintained in serum-free and serum-containing media for 4h (n=3-4), 8h (n=6), 24h (n=5) and 48h (n=5) under normoxic (21% O2) and hypoxic (1-2% O2) conditions to determine a time of maximum induction of both VEGF and PAI-1. Subsequently, cells were maintained for 48h in the presence or absence of siRNA for HIF-1[alpha], HIF-2[alpha], HIF-1[alpha] + -2[alpha], a non-targeting (NT) sequence or Cyclophilin B (CB). Media were then removed, cells lysed, and Western blotting used to assess HIF-[alpha] knockdown. VEGF and PAI-1 levels in the media were quantified by ELISA and results expressed as pg or ng/[micro]g protein. Results from 3 to 8 independent experiments were analyzed using unpaired t-tests. Under hypoxic conditions treatment of cells with HIF-1[alpha], HIF-2[alpha] or HIF -1[alpha] + -2[alpha] siRNA resulted in >90% HIF-Ñ protein knockdown as determined by Western blotting. 48h of hypoxic treatment caused a statistically significant increase in PAI-1 levels (p<0.01) and VEGF levels (p<0.001) compared to normoxic controls. Under hypoxic conditions, PAI-1 levels were 4.75 [plus-minus] 0.46 ng/[micro]g protein and VEGF levels were 7.27 [plus-minus] 1.08 pg/[micro]g protein. Treatment with siRNA to HIF-1[alpha], HIF-2[alpha] and HIF-1[alpha] + -2[alpha] significantly reduced PAI-1 levels to 3.3 [plus-minus] 0.35 (p<0.02), 3.1 [plus-minus] 0.38 (p<0.03) and 2.4 [plus-minus] 0.19 (p<0.003), respectively. No significant difference in PAI-1 reduction was noted between the three HIF siRNA conditions. Under hypoxic conditions, levels of VEGF in cells treated with siRNA to HIF-1[alpha] (5.79 [plus-minus] 0.55), HIF-2[alpha] (5.50 [plus-minus] 1.24) and HIF-1[alpha] + -2[alpha] (4.24 [plus-minus] 0.93) were reduced compared to the hypoxic control (7.27 [plus-minus] 1.08), yet these effects did not reach statistical significance. However, when compared with the levels observed in cells treated with NT siRNA (9.90 [plus-minus] .98), all HIF siRNA treatments promoted a significant reduction in VEGF expression (p<0.003, p<0.02 and p<0.003 for HIF-1[alpha], HIF-2[alpha] and HIF-1[alpha]+ -2[alpha], respectively). In conclusion, these results indicate that hypoxia-mediated changes in PAI-1 and VEGF expression in trophoblasts are regulated similarly by both HIF-1[alpha] and HIF-2[alpha]. This provides important insight into the molecular mechanisms regulating hemostasis and trophoblast invasion as well as their potential dysfunction in pregnancies complicated by preeclampsia
|
14 |
Plasminogen activator inhibitor-1 and the insulin resistance syndrome /Byberg, Liisa, January 2002 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 4 uppsatser.
|
15 |
Factors Affecting Ventricular Remodeling Post Myocardial InfarctionAgarwal, Udit 02 April 2010 (has links)
No description available.
|
16 |
Haemostatic markers and cardiovascular function in black and white South Africans : the SABPA study / Leandi LammertynLammertyn, Leandi January 2015 (has links)
Motivation
In the black population of South Africa, cardiovascular disease (CVD) is rapidly increasing due to
urbanisation. Stroke is usually accompanied by a prothrombotic haemostatic profile. Changing
lifestyle factors that accompany the urbanisation process could have a negative impact on the
haemostatic profile of black South Africans. Elevated levels of pro-coagulant factors, von
Willebrand factor (vWF), fibrinogen and fibrin D-dimer have been reported in the black population,
which could increase the black population’s susceptibility to CVD. However, low levels of
plasminogen activator inhibitor-1 (PAI-1) previously reported in the black population could
contribute towards a pro-fibrinolytic state, which may counteract the hypercoagulant state. This
may have a beneficial effect on the haemostatic profile of the black population. More investigation
into the haemostatic profile of black South Africans is therefore needed to determine if an altered
haemostatic profile exists in this group, and if so, to what extent these alterations may relate to
cardiovascular dysfunction. This study included markers of both the coagulation (vWF, fibrinogen,
fibrin D-dimer) and fibrinolytic (PAI-1, fibrin D-dimer and fibrinolytic potential) systems in an
attempt to investigate the haemostatic profile of the black population of South Africa, and for
comparison purposes that of the white population as well. The relationship of these markers’ with
selected markers of cardiovascular function was also examined to determine if they could possibly
contribute to an increase in cardiovascular risk, especially in the black population.
Aims
The aims of this study were to first compare coagulation and fibrinolysis markers in the black and
white populations of South Africa. Furthermore, to determine if associations exist between the
selected components of the haemostatic system and markers of cardiovascular function,
especially in the black population of South Africa, who tends to be at a higher cardiovascular risk
due to altered metabolic and haemostatic profiles.
Methodology
The Sympathetic activity and Ambulatory Blood Pressure in Africans (SABPA) study was a
prospective cohort study that consisted of 409 participants at baseline (2008-2009) that were
equally distributed according to both ethnicity (200 black; 209 white) and gender (black, 101 men,
99 women; white, 101 men, 108 women). At follow-up (2011/2012) the cohort totalled 359
participants (170 black, 88 men and 82 women; 189 white, 93 men and 96 women). Data from
baseline measurements were used for the first two manuscripts (chapters 2 and 3), while followup
data was used for the third manuscript (chapter 4). vWF, fibrinogen, PAI-1, fibrin D-dimer, CLT,
serum peroxides, glutathione, glutathione peroxidase and reductase activity were determined,
and ambulatory blood pressure and the retinal vessel calibres were measured. The groups were
stratified by ethnicity as specified by statistical interaction terms. T-tests and chi-square tests were
used to compare means and proportions, respectively. Pearson and partial regression analyses
were used to determine correlations between the components of the haemostatic system and
cardiovascular function markers. This was followed by multiple linear regression analyses to
investigate whether independent associations exist between the variables in both ethnic groups.
P-values ≤0.050 were deemed significant.
Results and conclusion of each manuscript
The first manuscript (chapter 2) compares the haemostatic profiles of the black and white
population to determine whether ambulatory blood pressure is related to components of the
haemostatic system. The black participants displayed a prothrombotic profile with significantly
higher vWF, fibrinogen, PAI-1, fibrin D-dimer and a longer CLT than their white counterparts.
Furthermore, partial and multiple linear regression analyses showed a positive association of
systolic and diastolic blood pressure with fibrin D-dimer in the black population, while a negative
association existed between ambulatory blood pressure and CLT in the white population. These
associations suggest that fibrin D-dimer may contribute, at least in part, to the high prevalence of
hypertension in the black population.
The second manuscript (chapter 3) determined associations between markers of the haemostatic
and oxidant-antioxidant systems in the black and white populations. In addition to the
prothrombotic profile that exists in the black population, this group also had significantly higher
serum peroxides (oxidative stress) and lower glutathione peroxidase activity (antioxidant) levels.
Multiple linear regression analyses indicated positive associations between fibrinogen and serum
peroxides in both populations. In the white population, an additional positive association was
found between serum peroxide and CLT. In the black population, vWF and CLT were negatively
associated with GPx activity. The results suggest that there are ethnic-specific relationships
between the haemostatic and oxidant-antioxidant systems.
The third manuscript (chapter 4) investigated the relationships between the retinal vessel calibres
and components of the haemostatic system in the black and white population. The investigation
focussed specifically on arteriolar diameters in the lower median, since a narrow arteriolar
diameter is known to be associated with elevated blood pressure. In both ethnic groups, a
narrower arteriolar calibre was accompanied by narrower venular calibres. Independent positive
associations were found between the central retinal vein equivalent (CRVE) and fibrinogen in the
black population, as well as vWF and CLT in the white population. In addition, independent
negative associations were found between the central retinal artery equivalent and CLT in the
black population and with vWF in the white population. The results suggest that haemostatic
alterations are linked to early vascular changes that may differ between ethnicities.
General conclusion
Ethnic-specific relationships between the components of the haemostatic system and measures
of cardiovascular function are evident. The prothrombotic profile that is observed in the black
population, together with the adverse associations of the haemostatic components with blood
pressure, a compromised oxidant-antioxidant profile, and retinal vessel calibres may contribute,
at least in part, to the high cardiovascular and cerebrovascular risk evident in this population
group. / PhD (Physiology), North-West University, Potchefstroom Campus, 2015
|
17 |
Haemostatic markers and cardiovascular function in black and white South Africans : the SABPA study / Leandi LammertynLammertyn, Leandi January 2015 (has links)
Motivation
In the black population of South Africa, cardiovascular disease (CVD) is rapidly increasing due to
urbanisation. Stroke is usually accompanied by a prothrombotic haemostatic profile. Changing
lifestyle factors that accompany the urbanisation process could have a negative impact on the
haemostatic profile of black South Africans. Elevated levels of pro-coagulant factors, von
Willebrand factor (vWF), fibrinogen and fibrin D-dimer have been reported in the black population,
which could increase the black population’s susceptibility to CVD. However, low levels of
plasminogen activator inhibitor-1 (PAI-1) previously reported in the black population could
contribute towards a pro-fibrinolytic state, which may counteract the hypercoagulant state. This
may have a beneficial effect on the haemostatic profile of the black population. More investigation
into the haemostatic profile of black South Africans is therefore needed to determine if an altered
haemostatic profile exists in this group, and if so, to what extent these alterations may relate to
cardiovascular dysfunction. This study included markers of both the coagulation (vWF, fibrinogen,
fibrin D-dimer) and fibrinolytic (PAI-1, fibrin D-dimer and fibrinolytic potential) systems in an
attempt to investigate the haemostatic profile of the black population of South Africa, and for
comparison purposes that of the white population as well. The relationship of these markers’ with
selected markers of cardiovascular function was also examined to determine if they could possibly
contribute to an increase in cardiovascular risk, especially in the black population.
Aims
The aims of this study were to first compare coagulation and fibrinolysis markers in the black and
white populations of South Africa. Furthermore, to determine if associations exist between the
selected components of the haemostatic system and markers of cardiovascular function,
especially in the black population of South Africa, who tends to be at a higher cardiovascular risk
due to altered metabolic and haemostatic profiles.
Methodology
The Sympathetic activity and Ambulatory Blood Pressure in Africans (SABPA) study was a
prospective cohort study that consisted of 409 participants at baseline (2008-2009) that were
equally distributed according to both ethnicity (200 black; 209 white) and gender (black, 101 men,
99 women; white, 101 men, 108 women). At follow-up (2011/2012) the cohort totalled 359
participants (170 black, 88 men and 82 women; 189 white, 93 men and 96 women). Data from
baseline measurements were used for the first two manuscripts (chapters 2 and 3), while followup
data was used for the third manuscript (chapter 4). vWF, fibrinogen, PAI-1, fibrin D-dimer, CLT,
serum peroxides, glutathione, glutathione peroxidase and reductase activity were determined,
and ambulatory blood pressure and the retinal vessel calibres were measured. The groups were
stratified by ethnicity as specified by statistical interaction terms. T-tests and chi-square tests were
used to compare means and proportions, respectively. Pearson and partial regression analyses
were used to determine correlations between the components of the haemostatic system and
cardiovascular function markers. This was followed by multiple linear regression analyses to
investigate whether independent associations exist between the variables in both ethnic groups.
P-values ≤0.050 were deemed significant.
Results and conclusion of each manuscript
The first manuscript (chapter 2) compares the haemostatic profiles of the black and white
population to determine whether ambulatory blood pressure is related to components of the
haemostatic system. The black participants displayed a prothrombotic profile with significantly
higher vWF, fibrinogen, PAI-1, fibrin D-dimer and a longer CLT than their white counterparts.
Furthermore, partial and multiple linear regression analyses showed a positive association of
systolic and diastolic blood pressure with fibrin D-dimer in the black population, while a negative
association existed between ambulatory blood pressure and CLT in the white population. These
associations suggest that fibrin D-dimer may contribute, at least in part, to the high prevalence of
hypertension in the black population.
The second manuscript (chapter 3) determined associations between markers of the haemostatic
and oxidant-antioxidant systems in the black and white populations. In addition to the
prothrombotic profile that exists in the black population, this group also had significantly higher
serum peroxides (oxidative stress) and lower glutathione peroxidase activity (antioxidant) levels.
Multiple linear regression analyses indicated positive associations between fibrinogen and serum
peroxides in both populations. In the white population, an additional positive association was
found between serum peroxide and CLT. In the black population, vWF and CLT were negatively
associated with GPx activity. The results suggest that there are ethnic-specific relationships
between the haemostatic and oxidant-antioxidant systems.
The third manuscript (chapter 4) investigated the relationships between the retinal vessel calibres
and components of the haemostatic system in the black and white population. The investigation
focussed specifically on arteriolar diameters in the lower median, since a narrow arteriolar
diameter is known to be associated with elevated blood pressure. In both ethnic groups, a
narrower arteriolar calibre was accompanied by narrower venular calibres. Independent positive
associations were found between the central retinal vein equivalent (CRVE) and fibrinogen in the
black population, as well as vWF and CLT in the white population. In addition, independent
negative associations were found between the central retinal artery equivalent and CLT in the
black population and with vWF in the white population. The results suggest that haemostatic
alterations are linked to early vascular changes that may differ between ethnicities.
General conclusion
Ethnic-specific relationships between the components of the haemostatic system and measures
of cardiovascular function are evident. The prothrombotic profile that is observed in the black
population, together with the adverse associations of the haemostatic components with blood
pressure, a compromised oxidant-antioxidant profile, and retinal vessel calibres may contribute,
at least in part, to the high cardiovascular and cerebrovascular risk evident in this population
group. / PhD (Physiology), North-West University, Potchefstroom Campus, 2015
|
18 |
Mecanismos moleculares envolvidos no fenótipo endotelial em resposta a estímulos físicos e químicos / Molecular mechanisms involved in endothelial phenotype in response to physical and chemical stimuliSilva, Thaís Girão da 01 August 2018 (has links)
O endotélio reveste a parede vascular e possui função essencial na manutenção da homeostase. A célula endotelial é capaz de perceber estímulos extracelulares, como fatores químicos e mecânicos, transmitir a informação para dentro da célula e regular sua função e fenótipo. Neste sentido, investigamos os mecanismos moleculares associados as células endoteliais em dois contextos importantes de intervenções vasculares 1) nos stents farmacológicos, onde a rapamicina exerce funções antiproliferativas e pró-trombogênicas, e 2) na revascularização cardíaca por ponte de safena, onde o alto estiramento mecânico exerce grande impacto no remodelamento vascular e no fenótipo da célula endotelial. A rapamicina pertence à classe de drogas limus, bastante utilizadas nos stents farmacológicos usados no procedimento de desobstrução vascular. Além de sua função antiproliferativa, exploramos os efeitos deletérios associados a pró-trombogênese. Os dados demonstraram que a rapamicina ativa o receptor de TGF independentemente de seu ligante TGFbeta, promovendo aumento na expressão da PAI-1 (pró-trombogênica), alteração no fenótipo endotelial (Transição endotélio-mesenquimal - EndMT) e na formação de fibras de estresse. Os efeitos observados são dependentes da ativação de Smad2 e independentes da via clássica antiproliferativa por mTOR. Experimentos in vivo mostraram que o tratamento com inibidor do receptor de TGF diminui os efeitos pró-trombogênicos e a expressão de PAI-1 induzidos pela rapamicina em artérias carótidas de camundongos. A ponte de safena é um procedimento bastante utilizado na cirurgia de revascularização cardíaca e a arterialização do segmento venoso submetido ao estresse hemodinâmico arterial resulta em remodelamento vascular, que influencia o sucesso do procedimento. Nossos dados demonstram que a célula endotelial humana de veia safena humana (hSVEC), susceptível as modificações do tipo EndMT induzido quimicamente (estímulo pró-fibrótico e pró-inflamatório), não expressou o mesmo comportamento em resposta ao aumento de estiramento mecânico que ocorre durante a arterialização venosa. Entretanto, detectamos uma pronunciada redução dos filamentos de actina, modulação no padrão de ativação da cofilina e na proporção de actina glomerular (G-actina) entre citoplasma e núcleo, com redução da biodisponibilidade de NO. De modo interessante, demonstramos que a redução no filamento de actina é específica para a célula endotelial venosa, não sendo observado em células endoteliais de origem arterial de aorta e coronária. Em conjunto, os dados mostram que 1) efeitos pró-trombogênicos associados a rapamicina são mediados por ativação do receptor de TGF independente do seu ligante e da atividade antiproliferativa da droga e 2) a adaptação da célula endotelial venosa ao estiramento mecânico envolve modulação da síntese/degradação de filamentos de actina e redução na biodisponibilidade de NO. Estes novos elementos sobre o mecanismo de transdução de estímulos químicos e físicos pelo endotélio poderão ser explorados terapeuticamente para modular a plasticidade endotelial em disfunções cardiovasculares / Endothelium is the inner layer in vascular wall and displays an essential role in the maintenance of cardiovascular homeostasis. Endothelial cell senses the extracellular stimuli, such as chemical and mechanical factors, transduce and process these signals to regulate cell function and phenotype. Here, we investigated molecular underpinning of the endothelial cells under two important scenarios: 1) in drug-eluting stents, where rapamycin exerts antiproliferative and undesirable prothrombogenic functions, and 2) in vein graft bypass surgery, where increased stretch modulates vascular remodeling and endothelial cell phenotype. Rapamycin belongs to the class of limus drugs and is widely used in drug eluting stents (DES) to vascular restenosis. In addition to its antiproliferative function, we explore the deleterious effects associated with prothrombogenesis. Our data demonstrated that rapamycin activates TGF receptor independent of its ligand TGFbeta, in concert with promotion of PAI-1 expression (prothrombogenic), changes in endothelial phenotype (Endothelial to Mesenchymal Transition - EndMT) and stress fibers induction. These effects are Smad2 dependent and independent of the classical antiproliferative mTOR pathway of rapamycin. Our in vivo experiments showed that TGF receptor inhibitor treatment decreases prothrombogenic effects and PAI-1 expression induced by rapamycin in mice carotid arteries. Saphenous vein is widely used in coronary artery bypass surgery (CABG) and the vein arterialization remodeling in response to the increased stress influences graft patency. Our data demonstrated that human saphenous vein endothelial cell (hSVEC) is susceptible to chemically induced endothelial-to-mesenchymal transition (EndMT) by pro-fibrotic and pro-inflammatory stimuli. On the other hand, physical stimulus associated with high stretch failed to induce EndMT. However, we detected a pronounced decrease of actin filaments, modulation of the cofilin activation, changes in the proportion of glomerular actin (G-actin) between cytoplasm and nucleus, and reduction of NO bioavailability. Interestingly, the reduction of actin fibers by high stretch is specific to venous endothelial cell since arterial endothelial cells from aorta, and coronary artery failed to display the response. Altogether, our data show that 1) the thrombogenic effects of rapamycin are mediated by TGF receptor activation independent of its ligand and independent of the antiproliferative pathway of the drug, and 2) the adaptation of venous endothelial cell to mechanical stretch involves synthesis/degradation of actin filaments and reduced NO bioavailability. These new elements on signal transduction of endothelial cells in response to chemical and physical stimuli may be therapeutically explored to modulate endothelial plasticity in cardiovascular disorders
|
19 |
Polimorfismo da região -675 do gene serpine1 (polimorfismo 4g5g) e sua associação com inibidor 1 da ativação do plasminogenio (pai-1), síndrome metabólica e risco cardiovascular em pessoas vivendo com hiv/aids: um estudo caso-controle aninhado à coorte.OLIVEIRA, Georgge Gomes 27 April 2015 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-12-15T14:53:15Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
VersaoAtualizada2016 - Tese Georgge Gomes Oliveira - varsão para biblioteca UFPE.pdf: 3290385 bytes, checksum: 2ddc23c4486bcc121a9ea222566d1f09 (MD5) / Made available in DSpace on 2016-12-15T14:53:15Z (GMT). No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
VersaoAtualizada2016 - Tese Georgge Gomes Oliveira - varsão para biblioteca UFPE.pdf: 3290385 bytes, checksum: 2ddc23c4486bcc121a9ea222566d1f09 (MD5)
Previous issue date: 2015-04-27 / Ministério da Saúde do Brasil / Estudos recentes mostram que a síndrome metabólica (SM) é freqüente nas pessoas vivendo com HIV/AIDS (PLWHA). A importância na identificação da SM baseia-se no aumento do risco em cinco vezes de desenvolver diabetes mellitus tipo 2 (DM2) e em duas vezes de apresentar doença cardiovascular (DCV) trombóticas, embora os fatores de hipercoagulabilidade não estejam incluídos nos critérios de definição da síndrome. A SM é caracterizada pela presença concomitante de fatores reconhecidamente aterogênicos em um mesmo indivíduo. A freqüência de DCV em PLWHA vem aumentando ao longo dos anos. O PAI-1 é uma proteína importante na cascata de fibrinólise e seu aumento está associado ao estado de hipercoagulabilidade. Sua regulação depende de fatores genéticos, dentre eles, destaca-se o polimorfismo 4G5G do gene SERPINE1. A participação de substâncias protrombóticas na doença cardiovascular é conhecida em pessoas sem HIV, porém menos elucidada em PLWHA. Diante disto o objetivo deste trabalho foi determinar a freqüência do polimorfismo 4G5G em pessoas que vivem com HIV e verificar se o polimorfismo tem associação com a expressão do PAI-1 plasmático, com SM e com risco cardiovascular (RCV) estimado pelo escore de Framingham. Também objetivamos verificar associação dos níveis de PAI-1 com RDC e com SM. Para tanto foi desenvolvido estudo transversal para determinação da freqüência do polimorfismo 4G5G do PAI-1 e estudo tipo caso-controle para verificar associações entre polimorfismos com níveis plasmáticos de PAI-1 com SM e depois com RCV. Também foram testadas associações com fatores de risco tradicionais. Para primeiro estudo a amostra foi 185 pessoas sorteadas de um grupo de 2074 participantes da Cohort AIDS-PE Study Group. A prevalência de heterozigose foi de 86,8% e homozigose para 4G4G de 4,4%. A média de idade foi de 40,5 (DP ± 9,9 anos). A mediana de PAI-1 ativado foi de 13,6 ng/mL (IQ: 10,8-17,5). A freqüência de SM foi de 37,9% e de dislipidemia de 82,4%. Não encontramos associação do polimorfismo com os níveis plasmáticos de PAI-1, nem com SM. Para o segundo estudo houve perda de 23, restando 162 pessoas das quais 72,8% era do sexo feminino e a média de idade foi de 40 anos. A freqüência de RDCV estimado > 10% foi de 10,5%. O alelo 4G esteve presente em 91,0% das pessoas (genótipos 4G4G e 4G5G). Não houve associação entre polimorfismo e RDCV estimado > 10% (OR=0,6; IC95% 0,1 – 3,7), nem diferença dos níveis de PAI-1 em relação ao RDCV estimado (RCV>10% 14,6 ng/ml x RDCV < 10% 14,1 ng/ml; ρ=0,9). Hipercolesterolemia foi associada com genótipo 5G5G do polimorfismo (OR: 3,3; IC95%: 1,25 – 10) e com níveis plasmáticos mais elevados do PAI-1 (colesterol não HDL (CNHDL) > 130 mg/dl = 15,6 ng/ml versus CNHDL < 130 ng/ml = 13,8 ng/ml; ρ=0,04). Nesse estudo, encontramos alta prevalência do heterozigose para o polimorfismo 4G5G em pessoas vivendo com HIV/AIDS, no nordeste do Brasil. Entretanto, não encontramos associação entre o polimorfismo estudado com níveis plasmáticos de PAI-1 nem com SM. Também não verificamos associação do polimorfismo 4G5G do PAI-1 nem dos níveis plasmáticos de PAI-1 com RCV>10% pelo escore de Framingham, mas houve com hipercolesterolemia. / Recent studies show that the metabolic syndrome (MS) is common in people living with HIV / AIDS (PLWHA). The importance of identifying MS is based on an increased risk of developing fivefold type 2 diabetes mellitus (T2DM) and twice presenting cardiovascular disease (CVD) thrombotic, although hypercoagulability factors are not included in the definition of criteria syndrome. MS is characterized by the concomitant presence of known atherogenic factors in the same individual. The frequency of CVD in PLWHA has increased over the years. The PAI-1 is an important protein in the fibrinolytic cascade and its increase is associated with the hypercoagulable state. Its regulation depends on genetic factors, among them stands out the 4G5G polymorphism SERPINE1 gene. The participation of prothrombotic substances in cardiovascular disease is known in people without HIV, but less elucidated in PLWHA. In view of this the objective of this study was to determine the frequency of 4G5G polymorphism in people living with HIV and verify that polymorphism is associated with the expression of PAI-1 plasma with MS and cardiovascular risk (RCVD) estimated by the Framingham score . We aim to also assess the association of PAI- 1 levels with CVD and with MS. For this cross-sectional study was developed to determine the frequency of 4G5G polymorphism of PAI- 1 and case-control study to examine associations between polymorphisms and plasma levels of PAI- 1 with SM and then RCVD. Associations were also tested with traditional risk factors. For the first study sample was randomly selected 185 people of a group of participants 2074 of AIDS-PE Cohort Study Group. The prevalence of heterozygosity was 86.8% and homozygous for 4G4G 4.4%. The average age was 40.5 (SD ± 9.9 years). The PAI-1 activated median was 13.6 ng/mL (CI: 10.8 to 17.5). The frequency of MS was 37.9% and 82.4% dyslipidemia. We did not find polymorphism association with plasma levels of PAI-1 or with SM. For the second study, there was loss of 23, leaving 162 people of which 72.8% were female and the average age was 40 years. The frequency of RDCV estimated> 10% was 10.5%. The 4G allele was present in 91.0% of people (4G4G and 4G5G genotypes). There was no association between polymorphism and RDCV estimated> 10% (OR = 0.6; 95% CI 0.1 to 3.7), or difference of PAI-1 levels relative to estimated RDCV (RCV> 10% 14.6 ng / ml x RDCV <10% 14.1 ng/ml; ρ = 0.9). Hypercholesterolemia was associated with 5G5G genotype polymorphism (OR: 3.3; 95% CI: 1.25 to 10) and higher plasma levels of PAI-1 (non-HDL cholesterol (CNHDL)> 130 mg / dl = 15.6 ng/ml CNHDL versus <130 ng/ml = 13.8 ng/ ml; ρ = 0.04). In this study, we found a high prevalence of heterozygous for the polymorphism 4G5G in people living with HIV/AIDS, in northeastern Brazil. However, we found no association between the polymorphism studied with plasma levels of PAI-1 or with SM. Nor do we find polymorphism association 4G5G of PAI-1 or plasma levels of PAI-1 with RCV> 10% by Framingham score, but happened to hypercholesterolemia.
|
20 |
Mecanismos moleculares envolvidos no fenótipo endotelial em resposta a estímulos físicos e químicos / Molecular mechanisms involved in endothelial phenotype in response to physical and chemical stimuliThaís Girão da Silva 01 August 2018 (has links)
O endotélio reveste a parede vascular e possui função essencial na manutenção da homeostase. A célula endotelial é capaz de perceber estímulos extracelulares, como fatores químicos e mecânicos, transmitir a informação para dentro da célula e regular sua função e fenótipo. Neste sentido, investigamos os mecanismos moleculares associados as células endoteliais em dois contextos importantes de intervenções vasculares 1) nos stents farmacológicos, onde a rapamicina exerce funções antiproliferativas e pró-trombogênicas, e 2) na revascularização cardíaca por ponte de safena, onde o alto estiramento mecânico exerce grande impacto no remodelamento vascular e no fenótipo da célula endotelial. A rapamicina pertence à classe de drogas limus, bastante utilizadas nos stents farmacológicos usados no procedimento de desobstrução vascular. Além de sua função antiproliferativa, exploramos os efeitos deletérios associados a pró-trombogênese. Os dados demonstraram que a rapamicina ativa o receptor de TGF independentemente de seu ligante TGFbeta, promovendo aumento na expressão da PAI-1 (pró-trombogênica), alteração no fenótipo endotelial (Transição endotélio-mesenquimal - EndMT) e na formação de fibras de estresse. Os efeitos observados são dependentes da ativação de Smad2 e independentes da via clássica antiproliferativa por mTOR. Experimentos in vivo mostraram que o tratamento com inibidor do receptor de TGF diminui os efeitos pró-trombogênicos e a expressão de PAI-1 induzidos pela rapamicina em artérias carótidas de camundongos. A ponte de safena é um procedimento bastante utilizado na cirurgia de revascularização cardíaca e a arterialização do segmento venoso submetido ao estresse hemodinâmico arterial resulta em remodelamento vascular, que influencia o sucesso do procedimento. Nossos dados demonstram que a célula endotelial humana de veia safena humana (hSVEC), susceptível as modificações do tipo EndMT induzido quimicamente (estímulo pró-fibrótico e pró-inflamatório), não expressou o mesmo comportamento em resposta ao aumento de estiramento mecânico que ocorre durante a arterialização venosa. Entretanto, detectamos uma pronunciada redução dos filamentos de actina, modulação no padrão de ativação da cofilina e na proporção de actina glomerular (G-actina) entre citoplasma e núcleo, com redução da biodisponibilidade de NO. De modo interessante, demonstramos que a redução no filamento de actina é específica para a célula endotelial venosa, não sendo observado em células endoteliais de origem arterial de aorta e coronária. Em conjunto, os dados mostram que 1) efeitos pró-trombogênicos associados a rapamicina são mediados por ativação do receptor de TGF independente do seu ligante e da atividade antiproliferativa da droga e 2) a adaptação da célula endotelial venosa ao estiramento mecânico envolve modulação da síntese/degradação de filamentos de actina e redução na biodisponibilidade de NO. Estes novos elementos sobre o mecanismo de transdução de estímulos químicos e físicos pelo endotélio poderão ser explorados terapeuticamente para modular a plasticidade endotelial em disfunções cardiovasculares / Endothelium is the inner layer in vascular wall and displays an essential role in the maintenance of cardiovascular homeostasis. Endothelial cell senses the extracellular stimuli, such as chemical and mechanical factors, transduce and process these signals to regulate cell function and phenotype. Here, we investigated molecular underpinning of the endothelial cells under two important scenarios: 1) in drug-eluting stents, where rapamycin exerts antiproliferative and undesirable prothrombogenic functions, and 2) in vein graft bypass surgery, where increased stretch modulates vascular remodeling and endothelial cell phenotype. Rapamycin belongs to the class of limus drugs and is widely used in drug eluting stents (DES) to vascular restenosis. In addition to its antiproliferative function, we explore the deleterious effects associated with prothrombogenesis. Our data demonstrated that rapamycin activates TGF receptor independent of its ligand TGFbeta, in concert with promotion of PAI-1 expression (prothrombogenic), changes in endothelial phenotype (Endothelial to Mesenchymal Transition - EndMT) and stress fibers induction. These effects are Smad2 dependent and independent of the classical antiproliferative mTOR pathway of rapamycin. Our in vivo experiments showed that TGF receptor inhibitor treatment decreases prothrombogenic effects and PAI-1 expression induced by rapamycin in mice carotid arteries. Saphenous vein is widely used in coronary artery bypass surgery (CABG) and the vein arterialization remodeling in response to the increased stress influences graft patency. Our data demonstrated that human saphenous vein endothelial cell (hSVEC) is susceptible to chemically induced endothelial-to-mesenchymal transition (EndMT) by pro-fibrotic and pro-inflammatory stimuli. On the other hand, physical stimulus associated with high stretch failed to induce EndMT. However, we detected a pronounced decrease of actin filaments, modulation of the cofilin activation, changes in the proportion of glomerular actin (G-actin) between cytoplasm and nucleus, and reduction of NO bioavailability. Interestingly, the reduction of actin fibers by high stretch is specific to venous endothelial cell since arterial endothelial cells from aorta, and coronary artery failed to display the response. Altogether, our data show that 1) the thrombogenic effects of rapamycin are mediated by TGF receptor activation independent of its ligand and independent of the antiproliferative pathway of the drug, and 2) the adaptation of venous endothelial cell to mechanical stretch involves synthesis/degradation of actin filaments and reduced NO bioavailability. These new elements on signal transduction of endothelial cells in response to chemical and physical stimuli may be therapeutically explored to modulate endothelial plasticity in cardiovascular disorders
|
Page generated in 0.0793 seconds