Treatment-Resistant Hypertension: An Update in Device Therapy

Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signaling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction, and variations in the renin-angiotensin-aldosterone system (RAAS)

Organoides de cérebro como modelos de doenças de Alzheimer e Parkinson: uma revisão narrativa sobre as perspectivas para medicina regenerativa e personalizada

Há muitos anos a cultura celular bidimensional (2D) é utilizada como modelo de estudo de doenças, possuindo grande importância na medicina regenerativa, apesar de ainda conter limitações significativas. A fim de contornar essas limitações, a cultura celular tridimensional (3D) propõe uma organização mais complexa e sustentável que pode ser produzida a partir de células-tronco adultas (ASCs), células-tronco embrionárias (ESCs) ou células-tronco pluripotentes induzidas (iPSCs). A cultura 3D possibilitou o cultivo de células em um ambiente mais próximo do fisiológico, levando à formação de distintos tecidos órgãos-específicos. Em outras palavras, a cultura de células 3D possibilita a criação de estruturas orgânicas muito semelhantes aos órgãos de um ser humano, tanto estruturalmente, quanto funcionalmente. Desse modo, tem-se o que é chamado de organoides. O uso dos organoides tem crescido exponencialmente em ambientes in vitro, permitindo a análise e observação dos diversos fenômenos fisiológicos existentes. Como exemplo, pode-se citar os organoides cerebrais (“mini-brains”) reproduzidos in vitro buscando delinear as peculiaridades e complexidades do cérebro humano, com o objetivo de compreender algumas disfunções neurológicas que acometem esse sistema, como as duas principais doenças neurodegenerativas: Doenças de Alzheimer e Parkinson. Portanto, os organoides cerebrais podem permitir notável avanço da medicina regenerativa aplicada a doenças neurodegenerativas, já que esses “mini-brains” podem ser produzidos a partir de células do próprio paciente. Isso permitirá intervenções personalizadas, como testagens farmacológicas, a fim de definir qual seria o melhor tratamento medicamentoso. Consequentemente, essa tecnologia pode permitir terapias mais eficientes e individualizadas - o que é fundamental para a Medicina Personalizada.For many years, two-dimensional (2D) cell culture has been used as a model to study diseases, having great importance in regenerative medicine, despite still having significant limitations. In order to circumvent these limitations, threedimensional (3D) cell culture proposes a more complex and sustainable organization that can be produced from adult stem cells (ASCs), embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs). The 3D culture enabledthe cultivation of cells in an environment closer to the physiological one, leading to the formation of different organspecific tissues. In other words, 3D cell culture makes it possible to create organic structures very similar to the organs of a human being, both structurally and functionally. In this way, we have what are called organoids. The use of organoids has grown exponentially in in vitro environments, allowing the analysis and observation of the various existing physiological phenomena. As an example, we can mention the brain organoids (“mini-brains”) reproduced in vitro, seeking to delineate the peculiarities and complexities of the human brain, in order to understand some neurological dysfunctions that affect this system, such as the two main neurodegenerative diseases: Alzheimer’s and Parkinson’s Diseases. Therefore, brain organoids may allow a remarkable advance in regenerative medicine applied to neurodegenerative diseases, as these “mini-brains” can be produced from the patient’s own cells. This will allow for personalized interventions, such as drug testing, in order to define what would be the best drug treatment. Consequently, this technology can enable more efficient and individualized therapies - which is fundamental for Personalized Medicine

Decoding resistant hypertension signalling pathways

Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signalling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction and variations in the renin–angiotensin–aldosterone system (RAAS). miRNAs comprise a family of small non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. miRNAs are involved in the development of both cardiovascular damage and hypertension. Little is known of the molecular mechanisms that lead to development and progression of this condition. This review aims to cover the potential roles of miRNAs in the mechanisms associated with the development and consequences of RH, and explore the current state of the art of diagnostic and therapeutic tools based on miRNA approaches

Organoides de cérebro como modelos de doenças de Alzheimer e Parkinson: uma revisão narrativa sobre as perspectivas para medicina regenerativa e personalizada

Há muitos anos a cultura celular bidimensional (2D) é utilizada como modelo de estudo de doenças, possuindo grande importância na medicina regenerativa, apesar de ainda conter limitações significativas. A fim de contornar essas limitações, a cultura celular tridimensional (3D) propõe uma organização mais complexa e sustentável que pode ser produzida a partir de células-tronco adultas (ASCs), células-tronco embrionárias (ESCs) ou células-tronco pluripotentes induzidas (iPSCs). A cultura 3D possibilitou o cultivo de células em um ambiente mais próximo do fisiológico, levando à formação de distintos tecidos órgãos-específicos. Em outras palavras, a cultura de células 3D possibilita a criação de estruturas orgânicas muito semelhantes aos órgãos de um ser humano, tanto estruturalmente, quanto funcionalmente. Desse modo, tem-se o que é chamado de organoides. O uso dos organoides tem crescido exponencialmente em ambientes in vitro, permitindo a análise e observação dos diversos fenômenos fisiológicos existentes. Como exemplo, pode-se citar os organoides cerebrais (“mini-brains”) reproduzidos in vitro buscando delinear as peculiaridades e complexidades do cérebro humano, com o objetivo de compreender algumas disfunções neurológicas que acometem esse sistema, como as duas principais doenças neurodegenerativas: Doenças de Alzheimer e Parkinson. Portanto, os organoides cerebrais podem permitir notável avanço da medicina regenerativa aplicada a doenças neurodegenerativas, já que esses “mini-brains” podem ser produzidos a partir de células do próprio paciente. Isso permitirá intervenções personalizadas, como testagens farmacológicas, a fim de definir qual seria o melhor tratamento medicamentoso. Consequentemente, essa tecnologia pode permitir terapias mais eficientes e individualizadas - o que é fundamental para a Medicina Personalizada

Análise de biomarcadores da matriz extracelular do coração de camundongos tratados com isoproterenol

Submitted by Caroline Paula ([email protected]) on 2020-01-07T12:13:42Z No. of bitstreams: 1 Dissertação Ricardo Final.pdf: 2015558 bytes, checksum: a9e42eea19cd8a058600bc1bf849e47d (MD5)Approved for entry into archive by Camila Silva ([email protected]) on 2020-01-15T20:14:13Z (GMT) No. of bitstreams: 1 Dissertação Ricardo Final.pdf: 2015558 bytes, checksum: a9e42eea19cd8a058600bc1bf849e47d (MD5)Made available in DSpace on 2020-01-21T12:27:36Z (GMT). No. of bitstreams: 1 Dissertação Ricardo Final.pdf: 2015558 bytes, checksum: a9e42eea19cd8a058600bc1bf849e47d (MD5) Previous issue date: 2015-02-12A hipertensão está associada a altas taxas de morbidade e mortalidade na população mundial. Os elevados níveis de pressão sanguínea produzem um intenso estresse tecidual, uma condição progressiva para o desenvolvimento de hipertrofia que compromete a eficiência cardíaca. Os biomarcadores existentes para predizer lesões do miocárdio não são capazes de demonstrar outras consequências resultantes dos processos patológicos lesivos, como hipertrofia, inflamação e isquemia e, por isso é necessário a identificação de marcadores que sejam mais específicos às condições estudadas. Com o intuito de encontrar tais marcadores que possam indicar uma situação de hipertrofia cardíaca, desenvolveu-se um modelo animal dessa condição por meio da administração de isoproterenol. Nesse modelo os miócitos murinos são induzidos à apoptose e os fibroblastos aumentam sua produção de colágeno e deposição de proteínas da matriz extracelular, alterando assim o perfil proteico. Para determinação desse perfil, realizou-se um processo de enriquecimento de proteínas denominado descelularização que remove o conteúdo celular e seus remanescentes nucleares, mas mantendo a integridade da matriz. Após o processo de enriquecimento utilizou-se a técnica de phage display para determinar a diversidade peptídica presente no tecido cardíaco hipertrófico. Nossos resultados demonstram hipertrofia cardíaca devido ao aumento do peso do coração em relação ao peso corporal e comprimento da tíbia, assim como alterações na frequência cardíaca e pressão arterial condizentes com o uso de isoproterenol. O processo de descelularização teve sua eficiência demonstrada pela quantidade mínima de conteúdo de DNA presente no tecido e pela visualização por meio de histologia e microscopia eletrônica da integridade da matriz destituída de conteúdo celular. A realização do phage display permitiu a seleção de peptídeos específicos presentes no músculo cardíaco hipertrófico. Em seguida, obteve-se o sequenciamento dessas moléculas de DNA que codificaram os peptídeos expressos na superfície dos fagos. Essa abordagem abre perspectivas para a descoberta de marcadores que podem predizer o desenvolvimento da condição patológica de hipertrofia.Hypertension is associated with high morbidity and mortality rates in the world population. High levels of blood pressure produce intense stress tissue, a progressive condition for the development of cardiac hypertrophy, which affects the efficiency of the heart. The existing biomarkers to predict myocardial lesions are not able to show other harmful consequences resulting from pathological processes such as hypertrophy, ischemia and inflammation, and therefore identification of markers that are more specific to the conditions studied is required. In order to find such markers that may indicate a cardiac hypertrophy situation, we used mice model for this condition which had received isoproterenol. In this model, the myocytes from those mices were induced to apoptosis, and fibroblasts had increased collagen production and extracellular matrix proteins deposition, so modifying protein profile. We used a procedure called decellurarization to determina protein profile. This procedure leads to an enrichment of protein contents by removing cell content and its nuclear remnants, while maintaining matrix integrity. After the enrichment procedure, phage display technique was used to determine the diversity of peptide present in hypertrophic cardiac tissue. Our results demonstrated that cardiac hypertrophy due to an increase in heart weight compared to the body weight and tibia´s length, as well as changes in heart rate and blood pressure were consistent with the administration of isoproterenol. The decellularization process had its efficiency demonstrated by the minimal amount of DNA content present in tissue and by browsing through histology and electron microscopy of cell integrity devoid of matrix content. After 3 rounds of selection using phage display technique specific peptides were identified in the hypertrophic heart muscle matrix. Then, we have obtained the DNA sequencing of those peptides which were expressed on phage surface. This approach opens up prospects for the discovery of markers that can predict the development of the pathological condition of hypertrophy

Influence of parasite load on renal function in mice acutely infected with Trypanosoma cruzi.

BACKGROUND: Chagas disease is a neglected tropical disease caused by Trypanosoma cruzi. Despite the vast number of studies evaluating the pathophysiological mechanisms of the disease, the influence of parasite burden on kidney lesions remains unclear. Thus, the main goal of this work was to evaluate the effect of T. cruzi infection on renal function and determine whether there was a correlation between parasite load and renal injury using an acute experimental model of the disease. METHODOLOGY/PRINCIPAL FINDINGS: Low, medium and high parasite loads were generated by infecting C57BL/6 mice with 300 (low), 3,000 (medium) or 30,000 (high) numbers of "Y" strain trypomastigotes. We found that mice infected with T. cruzi trypomastigotes show increased renal injury. The infection resulted in reduced urinary excretion and creatinine clearance. We also observed a marked elevation in the ratio of urine volume to kidney and body weight, blood urea nitrogen, chloride ion, nitric oxide, pro- and anti-inflammatory cytokines and the number of leukocytes in the blood and/or renal tissues of infected mice. Additionally, we observed the presence of the parasite in the cortical/medullary and peri-renal region, an increase of inflammatory infiltrate and of vascular permeability of the kidney. Overall, most renal changes occurred mainly in animals infected with high parasitic loads. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that T. cruzi impairs kidney function, and this impairment is more evident in mice infected with high parasitic loads. Moreover, these data suggest that, in addition to the extensively studied cardiovascular effects, renal injury should be regarded as an important indicator for better understanding the pan-infectivity of the parasite and consequently for understanding the disease in experimental models

Chronic Lymphocytic Leukemia (CLL): evaluation of AKT protein kinase and microRNA gene expression related to disease pathogenesis

The present study evaluated 56 patients diagnosed with Chronic Lymphocytic Leukemia (CLL) and a control group of 44 clinically healthy subjects with no previous history of leukemia. Genetic expressions of AKT and microRNAs were evaluated by quantitative PCR (qPCR). A significant increase in AKT gene expression in patients when compared to controls was observed (p = 0.017). When the patients were stratified according to Binet subgroups, a significant difference was observed between the subgroups, with this protein kinase appearing more expressed in the B+C subgroup (p = 0.013). Regarding miRNA expression, miR-let-7b and miR-26a were reduced in CLL patients, when compared to controls. However, no significant differences were observed in these microRNA expressions between the Binet subgroups (A versus B+C). By contrast, miR-21 to miR-27a oncogenes showed no expression difference between CLL patients and controls. AKT protein kinase is involved in the signaling cascade that occurs with BCR receptor activation, leading to increased lymphocyte survival and protection against the induction of cell death in CLL. Thus, increased AKT protein kinase expression and the reduction of miR-let-7b and miR-26a, both tumor suppressors, may explain increased lymphocyte survival in CLL patients and may be promising markers for the prognostic evaluation of this disease

Effect of <i>T. cruzi</i> parasite loads on vascular permeability in the kidney tissue.

<p>C57BL/6 mice were challenged with low, medium and high loads of trypomastigotes and at 9 day post-infection, the accumulation of Evans Blue in the renal tissues was assessed. In A–D, a representative image of Evans Blue accumulation in the kidney from each group is demonstrated. E shows the mean percentage ± SEM of Evans Blue accumulation in the renal parenchyma. *p≤0.05 indicates a significant difference when mice from the medium and highly infected groups were compared to the uninfected control mice.</p

Effect of <i>T. cruzi</i> parasite loads on cytokine and nitric oxide production in kidney tissues.

<p>C57BL/6 mice were challenged with low, medium and high loads of blood trypomastigotes. At 6, 9, 12 and 18 days post-infection they were euthanized and their kidneys were removed to measure the concentrations of cytokines and nitric oxide. The cytokines TNF-α (A–D), IFN-γ (E–H) and IL-10 (I–L) were measured according to the manufacturer’s instructions, using commercially available ELISA kits. For measurement of nitric oxide, the Griess reaction was used. The absorbance was read at 570 nm. *p≤0.05 indicates a significant difference when animals from the medium and highly infected groups were compared to the uninfected control mice.</p

Parasitemia and survival of mice in the acute stage of <i>T. cruzi</i> infection.

<p>C57BL/6 mice were challenged with 3×10² (low dose), 3×10³ (medium dose) or 3×10⁴ (high dose) blood trypomastigotes. Parasitemia (A) was determined by counting the number of parasites in 5 µL of blood collected from tail snips at the indicated time points. Each point represents the mean of individual values from 10 mice. In the survival curve (B), 10 animals were individually monitored for 30 days of infection. ^δ0p≤0.05 indicates a significant difference when the mice infected with medium-inoculum were compared to the mice infected with high inoculum, ^δ1p≤0.05 indicates a significant difference when the mice from the low-inoculum group were compared to the mice from the high-inoculum group, ^δ2p≤0.05 indicates a significant difference when mice from the low-inoculum group were compared to mice from the medium-inoculum group, and *p≤0.05 indicates a significant difference when animals from the infected groups were compared to the uninfected control mice.</p