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1.
Clin Exp Rheumatol ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38372717

RESUMO

OBJECTIVES: We aimed to study whether myocardial changes are already detectable by cardiac magnetic resonance (CMR) imaging at the time of rheumatoid arthritis (RA) diagnosis. METHODS: This single-centre prospective study included 39 treatment-naive patients with early rheumatoid arthritis (ERA, symptom duration <1 year) without any history of heart disease, and 38 age- and sex-matched healthy volunteers. The disease severity was assessed with clinical evaluation (Disease Activity Score-28 for Rheumatoid Arthritis with CRP (DAS28-CRP) score) and serological testing (rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA)). The ERA patients were classified into group A (DAS28-CRP score ≥3.2, positive RF and ACPA; n=17) and group B (not fulfilling the group A criteria). The ERA patients and healthy controls underwent 1.5T CMR. RESULTS: Group A patients had significantly higher myocardial global T1 relaxation times than the healthy controls, 987 [965, 1003] ms vs. 979 [960, 991] ms (median [IQR]; p=0.041). A significant difference in T1 was found in the basal, mid inferior and mid anterolateral segments. In a multivariate analysis, prolonged global T1 relaxation time was independently associated with female sex (95% CI [5.62, 51.31] ms, p=0.016), and group A status (95% CI [4.65, 39.01] ms p=0.014). CONCLUSIONS: At the time of diagnosis, ERA patients with a higher disease activity (DAS28-CRP score ≥3.2) and both positive RF and ACPA showed prolonged T1 relaxation times in basal myocardial segments. These segments could be most susceptible to the development of myocardial fibrosis, and a segmental reporting style could be useful when estimating the first signs of myocardial fibrosis.

2.
Am J Cardiol ; 211: 122-129, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37949341

RESUMO

Atrial fibrillation (AF) is common in patients with aortic stenosis (AS) and complicates the assessment of AS severity. The overlapping of symptoms in these 2 conditions may postpone valve replacement. This study aimed to evaluate the effect of AF on the severity assessment of AS and its impact on symptoms and quality of life (QoL). Patients with severe AS were prospectively recruited. Echocardiography, symptom questionnaires, and RAND-36 QoL assessment were performed preoperatively and 3 months postoperatively. The aortic valve calcium score (AVC) was measured using computed tomography. Of the 279 patients, 74 (26.5%) had AF. Patients with AF had lower mean gradients and 45.9% had a low-gradient phenotype, with a mean gradient <40 mm Hg, compared with 22.4% of those without AF (p <0.001). The AVC measurements revealed severe valve calcification equally in patients with or without AF (85.7% vs 87.7%, p = 0.78). Patients with AF were more symptomatic at baseline, with 50.0% versus 27.3% in New York Heart Association class III or higher (p <0.001), and after intervention. Patients with AF had more residual dyspnea (27.3% vs 12.0%, p = 0.007) and exercise intolerance (36.4% vs 17.0%, p = 0.002). The QoL improved significantly in both groups but was worse at baseline in patients with AF and remained impaired after intervention. In conclusion, low-gradient AS phenotype is overrepresented in patients with AF, but they have equally severe stenosis determined using AVC, despite the lower gradients. Patients with AF have more symptoms and worse QoL, but they improve significantly after intervention. In patients with AF, multimodality imaging is important in the assessment of AS severity.


Assuntos
Estenose da Valva Aórtica , Fibrilação Atrial , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico por imagem , Qualidade de Vida , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Ecocardiografia , Valva Aórtica/cirurgia , Índice de Gravidade de Doença
3.
J Am Heart Assoc ; 12(23): e029933, 2023 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-38038185

RESUMO

BACKGROUND: Coronary computed tomography angiography is increasingly used as the first-line test for suspected coronary artery disease. Its overuse in a low pretest probability (PTP) population may lead to low diagnostic yield without change in patient management. We evaluated the clinical consequences of the updated 2019 European Society of Cardiology (ESC) chronic coronary syndromes guidelines' PTP estimation and whether imaging could be safely deferred in patients with a low PTP. METHODS AND RESULTS: This retrospective cohort included all 1753 consecutive patients who underwent coronary computed tomography angiography for suspected coronary artery disease at Helsinki University Hospital between 2009 and 2017. PTP was calculated according to the 2013 and 2019 ESC guidelines. The overall mortality, cardiac deaths, myocardial infarctions, and hospitalizations for unstable angina were acquired from national registry data for 1 to 10 years of follow-up (median, 4 years). Updated 2019 ESC guidelines classified 72% of the patients as having low PTP, whose imaging could have been deferred. The revascularization rate (4.7%) and annual cardiac mortality (0.4%) were low in the 857 patients reclassified from the recommendation to test, according to the 2013 ESC guideline, to deferral of coronary computed tomography angiography, according to the new 2019 guideline. CONCLUSIONS: The updated 2019 ESC guideline PTP score aids clinicians in safely preventing the overuse of cardiac imaging in patients deemed at low PTP of coronary artery disease. Diagnostic yield, revascularization rate, and cardiac mortality are low in patients with low pretest risk.


Assuntos
Cardiologia , Doença da Artéria Coronariana , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Angiografia por Tomografia Computadorizada , Estudos Retrospectivos , Angiografia Coronária/métodos , Probabilidade
4.
PLoS One ; 18(3): e0282394, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36888600

RESUMO

BACKGROUND: Long-term symptoms are frequent after coronavirus disease 2019 (COVID-19). We studied the prevalence of post-acute myocardial scar on cardiac magnetic resonance imaging (CMR) in patients hospitalized due to COVID-19 and its association with long-term symptoms. MATERIALS AND METHODS: In this prospective observational single-center study, 95 formerly hospitalized COVID-19 patients underwent CMR imaging at the median of 9 months after acute COVID-19. In addition, 43 control subjects were imaged. Myocardial scar characteristic of myocardial infarction or myocarditis were noted from late gadolinium enhancement images (LGE). Patient symptoms were screened using a questionnaire. Data are presented as mean ± standard deviation or median (interquartile range). RESULTS: The presence of any LGE was higher in COVID-19 patients (66% vs. 37%, p<0.01) as was the presence of LGE suggestive of previous myocarditis (29% vs. 9%, p = 0.01). The prevalence of ischemic scar was comparable (8% vs. 2%, p = 0.13). Only two COVID-19 patients (7%) had myocarditis scar combined with left ventricular dysfunction (EF <50%). Myocardial edema was not detected in any participant. The need for intensive care unit (ICU) treatment during initial hospitalization was comparable in patients with and without myocarditis scar (47% vs. 67%, p = 0.44). Dyspnea, chest pain, and arrhythmias were prevalent in COVID-19 patients at follow-up (64%, 31%, and 41%, respectively) but not associated with myocarditis scar on CMR. CONCLUSIONS: Myocardial scar suggestive of possible previous myocarditis was detected in almost one-third of hospital-treated COVID-19 patients. It was not associated with the need for ICU treatment, greater symptomatic burden, or ventricular dysfunction at 9 months follow-up. Thus, post-acute myocarditis scar on COVID-19 patients seems to be a subclinical imaging finding and does not commonly require further clinical evaluation.


Assuntos
COVID-19 , Traumatismos Cardíacos , Miocardite , Humanos , Miocardite/complicações , Meios de Contraste , Cicatriz/complicações , Função Ventricular Esquerda , COVID-19/complicações , Gadolínio , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Traumatismos Cardíacos/complicações , Imagem Cinética por Ressonância Magnética/métodos , Valor Preditivo dos Testes
5.
J Imaging ; 9(3)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36976106

RESUMO

Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss' (inter) and Cohen's (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss' κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (p < 0.001) better agreement among observers. The intra-observer results show Cohen's κ values between 0.37 and 0.53 for all observers, except one with a low κ of -0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.

6.
Eur Heart J Cardiovasc Imaging ; 24(4): 404-412, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36624560

RESUMO

AIMS: Giant cell myocarditis (GCM) is an inflammatory cardiomyopathy akin to cardiac sarcoidosis (CS). We decided to study the findings of GCM on cardiac magnetic resonance (CMR) imaging and to compare GCM with CS. METHODS AND RESULTS: CMR studies of 18 GCM patients were analyzed and compared with 18 CS controls matched for age, sex, left ventricular (LV) ejection fraction and presenting cardiac manifestations. The analysts were blinded to clinical data. On admission, the duration of symptoms (median) was 0.2 months in GCM vs. 2.4 months in CS (P = 0.002), cardiac troponin T was elevated (>50 ng/L) in 16/17 patients with GCM and in 2/16 with CS (P < 0.001), their respective median plasma B-type natriuretic propeptides measuring 4488 ng/L and 1223 ng/L (P = 0.011). On CMR imaging, LV diastolic volume was smaller in GCM (177 ± 32 mL vs. 211 ± 58 mL, P = 0.014) without other volumetric or wall thickness measurements differing between the groups. Every GCM patient had multifocal late gadolinium enhancement (LGE) in a distribution indistinguishable from CS both longitudinally, circumferentially, and radially across the LV segments. LGE mass averaged 17.4 ± 6.3% of LV mass in GCM vs 25.0 ± 13.4% in CS (P = 0.037). Involvement of insertion points extending across the septum into the right ventricular wall, the "hook sign" of CS, was present in 53% of GCM and 50% of CS. CONCLUSION: In GCM, CMR findings are qualitatively indistinguishable from CS despite myocardial inflammation being clinically more acute and injurious. When matched for LV dysfunction and presenting features, LV size and LGE mass are smaller in GCM.


Assuntos
Cardiomiopatias , Miocardite , Sarcoidose , Humanos , Miocardite/diagnóstico por imagem , Meios de Contraste , Gadolínio , Espectroscopia de Ressonância Magnética , Sarcoidose/patologia , Células Gigantes/patologia , Imagem Cinética por Ressonância Magnética/métodos , Cardiomiopatias/patologia , Valor Preditivo dos Testes
7.
J Cardiovasc Magn Reson ; 23(1): 132, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34775954

RESUMO

BACKGROUND: Aortic valve stenosis (AS) is the most prevalent valvular disease in the developed countries. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) is an emerging imaging technique, which has been suggested to improve the evaluation of AS severity compared to two-dimensional (2D) flow and transthoracic echocardiography (TTE). We investigated the reliability of CMR 2D flow and 4D flow techniques in measuring aortic transvalvular peak systolic flow in patients with severe AS. METHODS: We prospectively recruited 90 patients referred for aortic valve replacement due to severe AS (73.3 ± 11.3 years, aortic valve area 0.7 ± 0.1 cm2, and 54/36 tricuspid/bicuspid), and 10 non-valvular disease controls. All the patients underwent echocardiography and 2D flow and 4D flow CMR. Peak flow velocity measurements were compared using Wilcoxon signed rank sum test and Bland-Altman analysis. RESULTS: 4D flow underestimated peak flow velocity in the AS group when compared with TTE (bias - 1.1 m/s, limits of agreement ± 1.4 m/s) and 2D flow (bias - 1.2 m/s, limits of agreement ± 1.6 m/s). The differences between values obtained by TTE (median 4.3 m/s, range 2.7-6.1 m/s) and 2D flow (median 4.5 m/s, range 2.9-6.5 m/s) compared to 4D flow (median 3.1 m/s, range 1.7-5.1 m/s) were significant (p < 0.001). The difference between 2D flow and TTE were insignificant (bias 0.07 m/s, limits of agreement ± 1.5 m/s). In non-valvular disease controls, peak flow velocity was measured higher by 4D flow than 2D flow (1.4 m/s, 1.1-1.7 m/s and 1.3 m/s, 1.1-1.5 m/s, respectively; bias 0.2 m/s, limits of agreement ± 0.16 m/s). CONCLUSIONS: CMR 4D flow significantly underestimates systolic peak flow velocity in patients with severe AS. 2D flow, in turn, estimated the AS velocity accurately, with measured peak flow velocities comparable to TTE.


Assuntos
Estenose da Valva Aórtica , Ecocardiografia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Humanos , Espectroscopia de Ressonância Magnética , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes
8.
Ann Med ; 47(5): 423-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26203686

RESUMO

Calcific aortic valve disease (CAVD) is a progressive pathological condition with no effective pharmacological therapy. To identify novel molecular pathways as potential targets for pharmacotherapy, we studied microRNA (miRNA) profiles of heavily stenotic aortic valves (AS). One of the most upregulated miRNAs in AS valves compared to control valves was miR-125b (1.4-fold; P < 0.05). To identify CAVD-related changes in gene expression, DNA microarray analysis was performed, including an intermediate fibro(sclero)tic stage of the disease. This revealed changes especially in genes related to inflammation and immune response, including chemokine (C-C motif) ligand 3 (CCL3) and 4 (CCL4). CCL3 mRNA level was increased 3.9-fold (P < 0.05) when AS valves were compared to control valves, and a 2.5-fold increase (P < 0.05) in CCL4 gene expression was observed when fibro(sclero)tic valves were compared to control valves. Both CCL3 and CCL4 localized to macrophages by immunofluorescence. To identify chemokine-miRNA target pairs, data from miRNA target prediction databases were combined with valvular miRNA and mRNA expression profiles. MiR-125b was computationally predicted to target CCL4, as confirmed experimentally in cultured human THP-1 macrophages. Collectively, miR-125b and CCL4 appear to be involved in the progression of CAVD and may offer novel therapeutic and diagnostic strategies related to this disease.


Assuntos
Estenose da Valva Aórtica/metabolismo , Valva Aórtica/metabolismo , Quimiocina CCL4/metabolismo , MicroRNAs/metabolismo , Calcificação Vascular/metabolismo , Quimiocina CCL3/genética , Quimiocina CCL3/metabolismo , Quimiocina CCL4/genética , Humanos , MicroRNAs/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/metabolismo , Regulação para Cima
9.
Atherosclerosis ; 235(2): 398-407, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24929820

RESUMO

OBJECTIVE: To clarify the potential mechanisms by which oxidized low-density lipoprotein (oxLDL) could contribute to the progression of aortic valve stenosis (AVS). METHODS: We investigated a total of 46 stenotic and 20 control human aortic valves. The mRNA expression levels of scavenger receptor class A type 1 (SR-A1), CD36, Lectin-like oxidized LDL receptor-1 (LOX-1), and scavenger receptor class B type 1 (SR-B1) were studied using qPCR. Their cellular distribution in the valves was assessed by immunohistochemistry, and the potential effects of oxLDL were studied in cultured myofibroblasts isolated from the aortic valves. RESULTS: In AVS, the proinflammatory SR-A1 and the angiogenic LOX-1 were upregulated (p = 0.003 and p = 0.002), whereas the antiangiogenic CD36 was downregulated (p = 0.02). The expression of the atheroprotective SR-B1 remained unchanged. Immunohistochemistry revealed that SR-A1 was expressed by macrophages, whereas the expression of CD36 and LOX-1 was confined to myofibroblasts and endothelial cells in the diseased valves. In cultured valvular myofibroblasts, mast cell-derived components and TNF-α induced LOX-1 expression (p = 0.05 and p < 0.001), whereas oxLDL promoted the expression of proinflammatory cytokines. Furthermore, the expression of osteoprotegerin, an inhibitor of valvular calcification, decreased in response to oxLDL. Finally, myofibroblasts derived from stenotic valves accumulated more DiI-labeled oxLDL than myofibroblasts derived from macroscopically healthy valves (p = 0.035), so revealing enhanced foam cell-forming potential of myofibroblasts in the diseased valves. CONCLUSION: This study unveils the presence of SR-A1, CD36, and LOX-1 in aortic valves and suggests potential mechanisms by which they may contribute to the pathological angiogenesis, inflammation, calcification, and lipid accumulation in AVS.


Assuntos
Estenose da Valva Aórtica/fisiopatologia , Antígenos CD36/metabolismo , Lipoproteínas LDL/metabolismo , Receptores Depuradores Classe A/metabolismo , Receptores Depuradores Classe E/metabolismo , Células Cultivadas , Progressão da Doença , Regulação para Baixo , Células Endoteliais/metabolismo , Humanos , Miofibroblastos/metabolismo , Osteoprotegerina/biossíntese , Receptores Depuradores Classe E/biossíntese , Regulação para Cima
10.
Atherosclerosis ; 221(2): 366-74, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22281299

RESUMO

OBJECTIVE: To investigate mechanisms of lymphangiogenesis in aortic valve stenosis (AS). METHODS: Lymphatic vessels were visualized with LYVE-1 staining in 20 control, 5 sclerotic, and 40 stenotic human aortic valves. Vascular endothelial growth factors (VEGFs) VEGF-C and VEGF-D, and their lymphangiogenic receptor VEGFR-3, and the angiogenic VEGFR-2 were analysed by quantitative real-time PCR and immunohistochemistry. Cultured myofibroblasts derived from human stenotic aortic valves, and cultured human mast cells were used to study VEGF-C regulation, and VEGF-C and VEGF-A were quantified from cell culture media by enzyme immunoassays. RESULTS: Lymphatic vessels, VEGF-C, VEGF-D, VEGFR-3 and VEGFR-2 all were present in the aortic valves. In AS, the number of lymphatic vessels and the expression of VEGF-D, VEGFR-3, and VEGFR-2 were increased. Moreover, the numbers of lymphatic vessels correlated positively with those of neovessels (r = 0.525, p = 0.001) and mast cells (r = 0.374, p = 0.017). Cultured valvular myofibroblasts produced VEGF-C, and addition of tumour necrosis factor alpha (TNF-α) to the cells augmented its secretion. In contrast, proteases released by activated human mast cells degraded VEGF-C. CONCLUSION: These results show that lymphangiogenesis is induced in advancing AS. Furthermore, valvular myofibroblasts and activated mast cells were identified as novel regulators of lymphangiogenesis in aortic valves.


Assuntos
Estenose da Valva Aórtica/metabolismo , Valva Aórtica/metabolismo , Linfangiogênese , Vasos Linfáticos/metabolismo , Mastócitos/metabolismo , Miofibroblastos/metabolismo , Valva Aórtica/patologia , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/patologia , Estenose da Valva Aórtica/fisiopatologia , Estudos de Casos e Controles , Células Cultivadas , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Vasos Linfáticos/patologia , Vasos Linfáticos/fisiopatologia , Mastócitos/patologia , Miofibroblastos/patologia , Peptídeo Hidrolases/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismo , Fator C de Crescimento do Endotélio Vascular/genética , Fator C de Crescimento do Endotélio Vascular/metabolismo , Fator D de Crescimento do Endotélio Vascular/genética , Fator D de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Proteínas de Transporte Vesicular/metabolismo
11.
Arterioscler Thromb Vasc Biol ; 30(6): 1220-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20299690

RESUMO

OBJECTIVE: To examine the proangiogenic potential of myofibroblasts and mast cells, 2 types of cells present in human aortic valves. METHODS AND RESULTS: Aortic valve stenosis is an active atheroinflammatory disease, characterized by the accumulation of inflammatory cells and the neovascularization of the valves. A total of 85 stenotic valves and 20 control valves were obtained during valve replacement surgery. The results of immunohistochemistry analysis revealed stenotic aortic valves that contained 3 types of neovessels: small microvessels, medium microvessels, and organized arterioles. The distribution density of the neovessels was significantly higher in stenotic valves than in control valves (P<0.001) and correlated positively with valvular calcification gradus (r=0.26, P=0.02) and mast cell density (r=0.38, P<0.001). In the neovascularized areas of stenotic aortic valves, mast cells contained vascular endothelial growth factor and were degranulated, indicating their activation. The stimulation of cultured myofibroblasts derived from aortic valves with a mast cell-preconditioned medium, hypoxic culture conditions, or tobacco smoke all induced vascular endothelial growth factor secretion in the myofibroblasts. Finally, mast cell tryptase was able to degrade the antiangiogenic molecule endostatin in vitro. CONCLUSIONS: Mast cells and myofibroblasts may accelerate the progression of aortic valve stenosis by altering the balance between angiogenic and antiangiogenic factors in the valves, thus promoting valvular neovascularization.


Assuntos
Estenose da Valva Aórtica/metabolismo , Degranulação Celular , Fibroblastos/metabolismo , Mastócitos/metabolismo , Neovascularização Patológica/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Idoso , Estenose da Valva Aórtica/patologia , Estenose da Valva Aórtica/fisiopatologia , Estudos de Casos e Controles , Hipóxia Celular , Células Cultivadas , Meios de Cultivo Condicionados/metabolismo , Endostatinas/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/patologia , Neovascularização Patológica/fisiopatologia , Fumaça/efeitos adversos , Fatores de Tempo , Nicotiana , Triptases/metabolismo
12.
Arterioscler Thromb Vasc Biol ; 26(8): 1791-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16728655

RESUMO

OBJECTIVE: To investigate the possible role of elastolytic cathepsins S, K, and V and their endogenous inhibitor cystatin C in adverse extracellular matrix remodeling of stenotic aortic valves. METHODS AND RESULTS: Stenotic aortic valves were collected at valve replacement surgery and control valves at cardiac transplantations. The expression of cathepsins S, K, and V and cystatin C was studied by conventional and real-time polymerase chain reaction and by immunohistochemistry. Total cathepsin activity in the aortic valves was quantified by a fluorometric microassay. When compared with control valves, stenotic valves showed increased mRNA expression of cathepsins S, K, and V (P<0.05 for each) and a higher total cathepsin activity (P<0.001). In stenotic valves, cystatin C mRNA was increased (P<0.05), and cystatin C protein was found particularly in areas with infiltrates of inflammatory cells. Both cathepsin S and cystatin C were present in bony areas of the valves, whereas cathepsin V localized to endothelial cells in areas rich of neovascularization. Incubation of thin sections of aortic valves with cathepsins S, K, and V resulted in severe disruption of elastin fibers, and this cathepsin effect could be blocked by adding cystatin C to the incubation system. CONCLUSIONS: Stenotic aortic valves show increased expression and activity of elastolytic cathepsins S, K, and V. These cathepsins may accelerate the destruction of aortic valvular extracellular matrix, so promoting the progression of aortic stenosis.


Assuntos
Estenose da Valva Aórtica/metabolismo , Valva Aórtica/metabolismo , Catepsinas/metabolismo , Cistatinas/metabolismo , Cisteína Endopeptidases/metabolismo , Estudos de Casos e Controles , Catepsina K , Catepsinas/genética , Cistatina C , Cistatinas/genética , Cisteína Endopeptidases/genética , Elastina/metabolismo , Fluorometria , Humanos , Imuno-Histoquímica , Técnicas In Vitro , RNA Mensageiro/metabolismo
13.
Eur Heart J ; 27(12): 1495-504, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16401677

RESUMO

AIMS: Aortic stenosis (AS) is characterized by extensive remodelling of the valves, including infiltration of inflammatory cells, extracellular matrix degradation, and fibrosis. The molecular mechanisms behind this adverse remodelling have remained obscure. In this article, we study whether cathepsin G, an angiotensin II (Ang II)-forming elastolytic enzyme, contributes to progression of AS. METHODS AND RESULTS: Stenotic aortic valves (n = 86) and control valves (n = 17) were analysed for cathepsin G, transforming growth factor-beta1 (TGF-beta1), and collagens I and III with RT-PCR and immunohistochemistry. Valvular collagen/elastin ratio was quantified by histochemistry. In stenotic valves, cathepsin G was present in mast cells and showed increased expression (P < 0.001), which correlated positively (P < 0.001) with the expression levels of TGF-beta1 and collagens I and III. TGF-beta1 was also present in mast cell-rich areas and cathepsin G induced losartan-sensitive TGF-beta1 expression in cultured fibroblasts. Collagen/elastin ratio was increased in stenotic valves (P < 0.001) and correlated positively with smoking (P = 0.02). Nicotine in cigarette smoke activated mast cells and induced TGF-beta1 expression in cultured fibroblasts. Fragmented elastin was observed in stenotic valves containing activated cathepsin G-secreting mast cells and in normal valves treated with cathepsin G. CONCLUSION: In stenotic aortic valves, mast cell-derived cathepsin G may cause adverse valve remodelling and AS progression.


Assuntos
Estenose da Valva Aórtica/etiologia , Catepsinas/fisiologia , Mastócitos , Serina Endopeptidases/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/enzimologia , Estenose da Valva Aórtica/fisiopatologia , Catepsina G , Catepsinas/metabolismo , Colágeno/metabolismo , Elastina/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Serina Endopeptidases/metabolismo , Fumaça , Nicotiana , Fator de Crescimento Transformador beta1/metabolismo
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