Integrin-linked kinase (ILK) is an important mechanoreceptor that mediates many cellular signaling pathways. Its dysregulation causes dilated cardiomyopathy and other complications in the heart. Restoration of ILK improves cardiac function and survival, but the exact mechanism is unknown. Recent studies in our lab suggest that the cardioprotective properties of ILK may be related to its regulation of sarco/endoplasmic reticulum calcium ATPase (SERCA2a). The protein expressions of ILK and SERCA2a are positively correlated based on adenoviral transduction of ILK and siRNA targeting ILK in human induced pluripotent stem cell-derived cardiomyocytes. From analysis of their calcium transients, ILK transduction resulted in increased beat rate and faster calcium clearance while siRNA knockdown produced the opposite effect. The use of SERCA-specific inhibitor thapsigargin nullified the observed effects of ILK transduction. Based on these results, we conclude that ILK’s cardioprotective properties are partly related to improving calcium handling in cardiomyocytes through the regulation of SERCA2a.

Background: Although Bevacizumab (BVZ) and Sunitinib (SNT) prolong survival in cancer patients, an unanticipated side-effect is cardiotoxicity. Early indices of left ventricular (LV) systolic dysfunction would be useful to address the cardiac safety of anti-cancer drugs. Objective: Whether cardiac biomarkers, tissue velocity imaging (TVI), and/or strain rate (SR) can detect early cardiac dysfunction. Methods: A total of 95 C57Bl/6 mice received one of the following drug regimens: i) 0.9% saline; ii) BVZ; or iii) SNT and followed for 14 days. Serial blood pressure, high sensitivity troponin I (hsTnI), and echocardiography were performed. Results: BVZ- and SNT-treated mice demonstrated an increase in mean arterial blood pressure, hsTnI, cardiac apoptosis, and loss of cell integrity. TVI and SR values confirmed early LV systolic dysfunction at day 8, compared to conventional LVEF at day 13. Conclusions: Novel imaging techniques can detect early LV systolic dysfunction in a model of drug-mediated cardiomyopathy.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 3 uppsatser.

Background: Hereditary transthyretin amyloidosis (ATTR) is a lethal disease in which misfolded transthyretin (TTR) proteins accumulate as insoluble aggregates in tissues throughout the body. A common mutation is the exchange of valine to methionine at place 30 (TTR V30M), a form endemically found in the northern parts of Sweden. The main treatment option for ATTR amyloidosis is liver transplantation as the procedure halts production of mutated transthyretin. The disease is associated with marked phenotypic diversity ranging from predominant cardiac complications to pure neuropathy. Two different types of fibril composition – one in which both fragmented and full-length TTR are present (type A) and one consisting of only full-length TTR (type B) have been suggested to account for some phenotypic differences. Cardiac amyloidosis is associated with increased myocardial thickness and the disease could easily be mistaken for other entities characterised by myocardial thickening, such as sarcomeric hypertrophic cardiomyopathy (HCM). The aims in this thesis were to investigate echocardiographic characteristics in Swedish ATTR amyloidosis patients, and to identify markers aiding in differentiating ATTR heart disease from HCM. Another objective was to examine the impact of fibril composition and sex on the phenotypic variation in amyloid heart disease. Methods: A total of 122 ATTR amyloidosis patients that had undergone thorough echocardiographic examinations were included in the studies. Analyses of ventricular geometry as well as assessment of systolic and diastolic function were performed, using both conventional echocardiographic methods and speckle tracking technique. ECG analysis was conducted in study I, allowing measurement of QRS voltage. In study I and study II ATTR patients were compared to patients with HCM. In addition, 30 healthy controls were added to study II. Results: When parameters from ECG and echocardiography were investigated, the results revealed that the combination of QRS voltage <30 mm (<3 mV) and an interventricular/posterior wall thickness quotient <1.6 could differentiate cardiac ATTR amyloidosis from HCM. Differences in degree of right ventricular involvement were also demonstrated between HCM and ATTR amyloidosis, where ATTR patients displayed a right ventricular apical sparing pattern whereas the inverse pattern was found in HCM. Analysis of fibril composition revealed increased LV wall thickness in type A patients compared to type B, but in addition type A women displayed both lower myocardial thickness and more preserved systolic function as compared to type A males. When cardiac geometry and function were evaluated pre and post liver transplantation in type A and B patients, significant deterioration was detected in type A but not in type B patients after liver transplantation. Conclusions: Increasing awareness of typical cardiac amyloidotic signs by echocardiography is important to reduce the risk of delayed diagnosis. Our classification model based on ECG and echocardiography could aid in differentiating ATTR amyloidosis from HCM. Furthermore, the apical sparing pattern found in the right ventricle may pose another clue for amyloid heart disease, although it requires to be studied further. Furthermore, we disclosed that type A fibrils, male sex and increasing age were important determinants of increased myocardial thickness. As type A fibril patients displayed rapid cardiac deterioration after liver transplantation other treatment options should probably be sought for this group of patients.

O sistema imune do hospedeiro acometido pela doença de Chagas tem sido alvo de importantes pesquisas que podem favorecer avanços no entendimento dos mecanismos patogênicos relacionados à doença. No presente estudo, investigamos possíveis ações benéficas provenientes de efeitos anti-inflamatórios e antioxidantes da associação terapêutica (melatonina/meloxicam) sobre a cardiomiopatia chagásica crônica. Foram analisadas citocinas e outros mediadores envolvidos no processo inflamatório característico da infecção. Além disso, níveis plasmáticos de Creatina Fosfoquinase MB (CK-MB), número de focos inflamatórios no tecido cardíaco e análise do peso relativo do coração foram avaliados como fatores preditivos da redução dos danos no miocárdio após os diferentes tratamentos. Como modelo experimental, foram utilizados ratos wistar infectados pela cepa Y de T. cruzi e tratados ou não com melatonina, meloxicam, ou associação de ambos. As células inflamatórias e o parasitismo tecidual cardíaco foram avaliados por meio de técnica histológica. A técnica ELISA foi utilizada para detecção e quantificação de citocinas pró-inflamatórias e modulatórias no miocárdio e nos soros dos animais experimentais. Também foram investigados os níveis de nitrito produzidos por macrófagos e por células cardíacas dos grupos experimentais pela reação de Griess. Os parâmetros foram investigados durante a fase: crônica (90, 120 e 180) dias após a infecção. O estudo poderá contribuir para um melhor entendimento das respostas imunológicas anti-T. cruzi, bem como da patogenia da disfunção cardíaca chagásica crônica. / The host immune system affected by Chagas disease has been the subject of important research that can promote advances in the understanding the pathogenic mechanisms related to the disease. In the present study, it was investigated the possible beneficial actions of the anti-inflammatory and antioxidant combination therapy (melatonin / meloxicam) on chronic Chagas cardiomyopathy. Some cytokines and other mediators involved in the inflammatory process characteristic of infection were analyzed. In addition, plasma levels of creatine phosphokinase MB (CK-MB), number of inflammatory foci in the cardiac tissue and analysis of the relative weight of the heart were evaluated as predictors of damage reduction in the myocardium after different treatments. As experimental model, we used Wistar rats infected with the Y strain of T. cruzi. Some groups were untreated and others treated with melatonin, meloxicam, or combination of both. Inflammatory cells and heart tissue parasitism were evaluated by histological technique. Some pro-inflammatory and modulatory cytokines were quantified by ELISA technique in the myocardium and serum from experimental animals. The production of nitrite by macrophages and cardiac cells of the experimental groups was also investigated through Griess reaction. The parameters were observed during the chronic stage: (90, 120, and 180) days after infection. The study may contribute to a better understanding of the anti-T. cruzi immunological responses, as well as the pathogenesis of chronic Chagas heart dysfunction.

Studies to gain mechanistic understanding of heart dysfunction based on animal and traditional cell culture models have significant limitations. Animal models are low throughput and fail to recapitulate many aspects of human cardiac biology, and 2D culture models utilizing human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) are higher throughput but fail to incorporate one or more in vivo parameters, such as 3D architecture, electrical pacing and mechanical constraint. High throughput 3D tissue platforms could better recapitulate the in vivo microenvironment of cardiac tissue. Previous work from our group demonstrated an approach to build 3D cardiac microtissues based on photolithography-based fabrication of a MEMS device, but design limitations prevented further iterations. In this work, we used a 3D printing approach to engineer iPSC-CM-derived cardiac microtissues with different form factors. Microtissues generated in this platform increased in lifespan compared to the first-generation platform by more than 100%. When modeling mutations associated with genetic cardiomyopathy, functional and structural differences were observed between tissues composed of wild-type and mutant iPSC-CMs. These findings suggest that this micro-device platform can be potentially used for both mechanistic and drug discovery studies. / 2020-07-02T00:00:00Z

Diabetes mellitus (DM) é um grupo de anomalias metabólicas caracterizadas principalmente pela hiperglicemia. Componentes macro- e microvasculares, além de neuropáticos inter-relacionados com a elevação da glicemia são fatores freqüentemente envolvidos em acidentes cérebro-vasculares, infartos miocárdicos, doença vascular periférica, retinopatia e nefropatia diabética. Na literatura científica atual pode-se obter um grande número de trabalhos onde o uso de plantas medicinais, extratos ou substâncias vegetais isoladas é positivamente relacionado ao tratamento do DM e/ou seus efeitos diretos e indiretos. Bauhinia microstachya (RADDI) MACBR. (Caesalpinaceae) é uma planta que ocorre naturalmente na região sul do Brasil onde é conhecida popularmente como “escada-de-macaco”. Algumas populações fazem uso de preparações das folhas no tratamento do DM e suas complicações. Neste trabalho propomos que os extratos aquoso e hidro-etanólico, obtidos das folhas de B. microstachya possuem ação antioxidante in vitro e que o extrato hidro-etanólico apresenta poder antioxidante in vivo, além de efeito hipoglicemiante, apesar de ser potencialmente hepatotóxico. / Diabetes mellitus (DM) is a heterogeneous group of metabolic disorders characterized by chronic hyperglycemia. Both DM types share aspects that are related to uncontrolled hyperglycaemia: alterations in the carbohydrate, fat, and protein metabolism. In addition, increased cardiovascular disease risk, retinopathy, nephropathy, and neuropathy are vascular complications associated to diabetes. In scientific literature there are several reports where the use of folk medicine is positively related to DM treatment and/or their direct and indirect effects. Bauhinia microstachya (RADDI) MACBR. (Caesalpinaceae) is a creeper plant that occurs naturally in southern Brazil where is popularly known as “escada-de-macaco” (monkey’s ladder) and often used as herbal antidiabetic medicine. In the present work, we propose that the extracts obtained from B. microstachya leaves have in vitro and in vivo antioxidant action, hypoglycemic effect, despite their hepatotoxic potential.

Made available in DSpace on 2015-07-22T20:50:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-26. Added 1 bitstream(s) on 2015-08-11T03:25:26Z : No. of bitstreams: 1 Publico-0021a.pdf: 1600053 bytes, checksum: 7857382dabdbe2c1244a470f04a307d0 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:26Z : No. of bitstreams: 2 Publico-0021a.pdf: 1600053 bytes, checksum: 7857382dabdbe2c1244a470f04a307d0 (MD5) Publico-0021b.pdf: 1840605 bytes, checksum: 6332e90958fa262a4e0df6f8545a5303 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:26Z : No. of bitstreams: 3 Publico-0021a.pdf: 1600053 bytes, checksum: 7857382dabdbe2c1244a470f04a307d0 (MD5) Publico-0021b.pdf: 1840605 bytes, checksum: 6332e90958fa262a4e0df6f8545a5303 (MD5) Publico-0021c.pdf: 2001738 bytes, checksum: a1284696a0e1de7fec9bd415286e36b2 (MD5) / INTRODUÇÃO: Taquicardias Ventriculares Sustentadas (TVs) epicárdicas são comuns na Cardiopatia Chagásica Crônica (CCC). A ablação por cateter com radiofrequência, pode ser realizada com o auxílio de mapeamento eletroanatômico. O mapeamento eletroanatômico, por sua vez, necessita de definição especial, que pode ser incrementada com a integração de imagens oriundas de Tomografia Computadorizada do coração (TC do coração). A TC do coração pode fornecer a localização das áreas de fibrose, a extensão do comprometimento miocárdico, as características da anatomia coronariana e a função ventricular (esquerda e direita). Enquanto o acoplamento de imagens foi exaustivamente estudado no endocárdio, o acoplamento epicárdico e as informações advindas da aquisição de tomografia pré-procedimento não foram adequadamente avaliados até o momento. OBJETIVOS: Determinar a viabilidade técnica e a acurácia do mapeamento eletroanatômico com a integração de imagens associadas à TC em pacientes com TVS e CCC. Avaliar a precisão da TC em delimitar áreas de miocárdio anormal em comparação com o mapeamento eletroanatômico em portadores de CCC e TVS. MÉTODOS E RESULTADOS: Foi realizado o mapeamento e a ablação endocárdica e epicárdica em 8 pacientes portadores de CCC e TVS utilizando Carto® XP e sistema de integração de imagens Carto® Merge. A integração de imagens foi realizada utilizando TC em 3 fases para a obtenção do escore de cálcio, angiotomografia de coronárias e realce tardio. Para a comparação das imagens tridimensionais do sistema de mapeamento eletroanatômico e bidimensional da fluoroscopia, foi utilizado um editor gráfico vetorial. Este permitiu a comparação da distância entre a posição do cateter observado pela fluoroscopia e a obtida pelo mapa eletroanatômico. A diferença média entre os métodos analisados foi de 6,03mm (DP ±2,09mm). Cicatrizes estavam presentes no endocárdio e epicárdio de ambos ventrículos, sendo encontradas mais frequentemente na região póstero-basal de VE. A análise da contratilidade segmentar demonstrou-se superiora à técnica de realce tardio para a localização de miocárdio anormal conforme delimitado pelo mapeamento eletroanatomico em sensibilidade, valor preditivo positivo, acurácia e concordância. CONCLUSÃO: A combinação de mapeamento eletroanatômico e TC é tecnicamente possível e pode fornecer informações importantes para a ablação de pacientes com TV e CCC. / BACKGROUND: Chronic Chagasic Cardiomiopathy (CCC) is a parasitic disease where epicardial VTs are common. Eletroanatomic mapping merged with CT scan data is a useful tool for mapping the endocardium, and its accuracy in guiding ablation on the epicardium was not adequately evaluated . OBJECTIVE: Compare electronatomic map merged with Heart CT to fluoroscopy for epicardial ablation of CCC. Describe the distribution of the scars on CCC. METHODS AND RESULTS: We performed epicardial and endocardial mapping and ablation using electroanatomic mapping on eight patients and merged the map with coronary arteries CT Scan using at least three landmarks. To compare the 3D image obtained with 3dEA mapping with image integration capabilities and the 2D fluoroscopic image obtained during the ablation procedure we used vectorial computer graphic software in order to prove the images were equivalent and to compare the distance between the catheter tip on fluoroscopy to catheter tip on 3D EA map. EPRFCA was successfully performed in all patients and they did not present recurrence for at least 3 months follow up. The mean difference between the tip of the catheter on fluoroscopy and on the 3D model was 6.03 ± 2.09mm. Scars were present in the epicardium and endocardium and most of patients presented with posterior wall scars and RV scar. CONCLUSION: The combination of electroanatomic map and heart CT scan data is feasible and can be an important tool for EPRFCA in patients with CCC and VT. / TEDE / BV UNIFESP: Teses e dissertações

La cardiomyopathie dilatée est l'une des principales causes d'insuffisance cardiaque en Europe. Dans le cadre de la cardiomyopathie liée aux mutations du gène LMNA, en dépit des soins médicaux conventionnels, aucun traitement satisfaisant ne permet de pallier à la dilatation cardiaque progressive et à la perte de la contractilité. Le gène LMNA code pour les lamines nucléaires de type A, qui sont les principaux constituants de la lamina nucléaire. De précédents travaux démontrent que l'activation anormale de ERK 1/2 est impliquée dans la pathophysiologie de la cardiomyopathie dilatée liée aux mutations du gène LMNA. L'inhibition de la voie ERK 1/2 ralentit également la progression de la fibrose myocardique, relativement développée chez l'homme, en cas de cardiomyopathie dilatée. Dans le cadre de ma thèse, j’ai suggéré que l'activité aberrante de la voie TGF-β pourrait participer à l’activation anormale de ERK 1/2 et être impliquée dans la physiopathologie de dysfonction contractile ventriculaire gauche dans la cardiomyopathie liée aux mutations du gène LMNA. Les mécanismes moléculaires sous-jacents à la modulation de la signalisation ERK1/2, causée dans le cœur, par les mutations du gène LMNA, restent totalement incertains. De ce fait, j'ai testé l'hypothèse selon laquelle la modulation anormale de ERK1/2 induirait l'altération des cibles cytosoliques et modifierait le réseau du cytosquelette cardiaque. Mon travail a mis en évidence un nouveau partenaire de la forme active (phosphorylée) d’ERK1/2 : cofiline-1. La cofiline induit la déramification des filaments d'actine. Ce projet met en lumière un rôle inattendu joué par la signalisation ERK1/2 dans la dynamique de l'actine et dans le développement de la dysfonction ventriculaire gauche de la cardiomyopathie liée aux mutations du gène LMNA. / Dilated cardiomyopathy is one of the leading causes of heart failure in Europe. Despite of the conventional medical care, there is no definitive treatment for the progressive cardiac dilatation and loss of contractility in LMNA cardiomyopathy often leading to sudden death or heart transplantation. LMNA gene encodes nuclear A-type lamins, which are the main constituents of the nuclear lamina. Previous studies clearly show that the abnormal ERK1/2 activation is involved in the pathophysiology of LMNA dilated cardiomyopathy. However, its role in the development of cardiac dysfunction remains unclear. Inhibition of ERK1/2 signaling also slows progression of myocardial fibrosis, which is prominent in humans with dilated cardiomyopathy. I suggested that aberrant TGF-β signaling activity could participate to the abnormal ERK1/2 activation and be involved is the pathophysiology of left-ventricular contractile dysfunction in LMNA cardiomyopathy. Given that the understanding of molecular and cellular mechanisms underlying the modulation of ERK1/2 signaling in the heart caused by LMNA mutation remains totally unclear, I tested the hypothesis that ERK1/2 abnormal modulation leads to alteration of cytosolic targets and alter cardiac cytoskeleton network. My work highlighted a novel partner of activated (phosphorylated) ERK1/2, ADF/cofilin-1. Cofilin promotes debranching of actin filaments. I showed that disrupted actin dynamics leads to abnormal sarcomere structure. This project unraveled an unexpected role played by ERK1/2 signaling in actin dynamics and in the development of left-ventricular dysfunction in LMNA cardiomyopathy.

Diabetes mellitus (DM) é um grupo de anomalias metabólicas caracterizadas principalmente pela hiperglicemia. Componentes macro- e microvasculares, além de neuropáticos inter-relacionados com a elevação da glicemia são fatores freqüentemente envolvidos em acidentes cérebro-vasculares, infartos miocárdicos, doença vascular periférica, retinopatia e nefropatia diabética. Na literatura científica atual pode-se obter um grande número de trabalhos onde o uso de plantas medicinais, extratos ou substâncias vegetais isoladas é positivamente relacionado ao tratamento do DM e/ou seus efeitos diretos e indiretos. Bauhinia microstachya (RADDI) MACBR. (Caesalpinaceae) é uma planta que ocorre naturalmente na região sul do Brasil onde é conhecida popularmente como “escada-de-macaco”. Algumas populações fazem uso de preparações das folhas no tratamento do DM e suas complicações. Neste trabalho propomos que os extratos aquoso e hidro-etanólico, obtidos das folhas de B. microstachya possuem ação antioxidante in vitro e que o extrato hidro-etanólico apresenta poder antioxidante in vivo, além de efeito hipoglicemiante, apesar de ser potencialmente hepatotóxico. / Diabetes mellitus (DM) is a heterogeneous group of metabolic disorders characterized by chronic hyperglycemia. Both DM types share aspects that are related to uncontrolled hyperglycaemia: alterations in the carbohydrate, fat, and protein metabolism. In addition, increased cardiovascular disease risk, retinopathy, nephropathy, and neuropathy are vascular complications associated to diabetes. In scientific literature there are several reports where the use of folk medicine is positively related to DM treatment and/or their direct and indirect effects. Bauhinia microstachya (RADDI) MACBR. (Caesalpinaceae) is a creeper plant that occurs naturally in southern Brazil where is popularly known as “escada-de-macaco” (monkey’s ladder) and often used as herbal antidiabetic medicine. In the present work, we propose that the extracts obtained from B. microstachya leaves have in vitro and in vivo antioxidant action, hypoglycemic effect, despite their hepatotoxic potential.