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1.
Rev. Ciênc. Plur ; 8(3): 27644, out. 2022. ilus, tab
Article in Portuguese | LILACS, BBO | ID: biblio-1399339

ABSTRACT

Introdução:uma vez conhecidos os mecanismos de patogênese do SARS-CoV-2, vários métodos de tratamento para a COVID-19 foram desenvolvidos, dentre eles destaca-se o uso dos anticorpos monoclonais para o contexto de pacientes em estágios graves da doença. Objetivo: compreender se o uso dos anticorpos monoclonais para tratamento da COVID-19 grave interfere nos níveis séricos da angiotensina II. Metodologia:Para a realização dessa pesquisa foram selecionados através do DeCS e MeSH os descritores "COVID-19", "Angiotensin II" e "Antibodies, Monoclonal" e seus respectivos "entry terms" sugeridos pela base MeSH. Posteriormente,utilizando-se os operadores booleanos OR e AND, foi montada uma estratégia de busca, a qual foi utilizada nas bases de dados PUBMED, EMBASE, Web of Science, Cochrane Library e Scopus, sem restrição dedata de publicação ou idioma. Resultados:ao final do processo de seleção dos artigos, 29 foram selecionados para a leitura e análise completa. Nesta revisão, foram abordados diferentes tipos de anticorpos monoclonais, os quais foram oportunamente agrupados de acordo com o seu mecanismo de ação. Conclusão: foi possível concluir que das cinco classes de anticorpos monoclonais tratadas neste trabalho, três potencialmente podem causar alterações nos níveis séricos de angiotensina II (AU).


Introduction:once the mechanisms of pathogenesis of SARS-CoV-2 are known, several methods of treatment for COVID-19 have been developed, among them the use of monoclonal antibodies for the context of patients in severe stages of the disease. Purpose:to understand whether the use of monoclonal antibodies for the treatment of severe COVID-19 interferes with serum angiotensin II levels. Methodology:For this research were selected through DeCS and MeSH the descriptors "COVID-19", "Angiotensin II" and "Antibodies, Monoclonal" and their respective entry "Terms" suggested by the MeSH database. Subsequently, using the boolean operators OR and AND, a search strategy was set up, which was used in the databases PUBMED, EMBASE, Web of Science, Cochrane Library and Scopus, without restriction of publication date or language. Results:at the end of the article selection process, 29 were selected for reading and full analysis. In this review, different types of monoclonal antibodies were addressed, which were opportunely grouped according to their mechanism of action. Conclusion:it was possible to conclude that of the five classes of monoclonal antibodies treated in this study, three potentially can cause changes in serum levels of angiotensin II (AU).


Introducción:Una vez conocidos los mecanismos de patogénesis del SARSCoV-2, se desarrollaron variosmétodos de tratamiento para el COVID-19, entre ellos, el uso de anticuerpos monoclonales para el contexto de pacientes en fases graves de la enfermedad. Objetivo:Comprender si el uso de anticuerpos monoclonales para el tratamiento de la COVID-19 grave interfiere en los niveles séricos de angiotensina II. Metodología:Los descriptores "COVID-19", "Angiotensina II", "Anticuerpos, Monoclonales" y sus respectivos "entry terms" (términos de entrada) sugeridos por el MeSH fueron seleccionados a través de DeCS yMeSH. Posteriormente, utilizando los operadores booleanos OR y AND, se estableció una estrategia de búsqueda que se utilizó en las bases de datos PUBMED, EMBASE, Web of Science, Cochrane Library y Scopus, sin restricción de fecha de publicación ni de idioma. Resultados:Al final del proceso de selección de artículos, se seleccionaron 29 artículos para su lectura y análisis completos. En esta revisión se han abordado diferentes tipos de anticuerpos monoclonales, que se han agrupado oportunamente según su mecanismo de acción. Conclusión:Se pudo concluir que de las cinco clases de anticuerpos monoclonales tratados en este trabajo, tres pueden potencialmente causar alteraciones en los niveles séricos de angiotensina II (AU).


Subject(s)
Angiotensin II , COVID-19/drug therapy , Immunologic Factors/therapeutic use , Antibodies, Monoclonal/therapeutic use , SARS-CoV-2/enzymology
2.
Article in Chinese | WPRIM | ID: wpr-927990

ABSTRACT

To investigate the effects of leonurine(Leo) on abdominal aortic constriction(AAC)-induced cardiac hypertrophy in rats and its mechanism. A rat model of pressure overload-induced cardiac hypertrophy was established by AAC method. After 27-d intervention with high-dose(30 mg·kg~(-1)) and low-dose(15 mg·kg~(-1)) Leo or positive control drug losartan(5 mg·kg~(-1)), the cardiac function was evaluated by hemodynamic method, followed by the recording of left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVESP), as well as the maximum rate of increase and decrease in left ventricular pressure(±dp/dt_(max)). The degree of left ventricular hypertrophy was assessed based on heart weight index(HWI) and left ventricular mass index(LVWI). Myocardial tissue changes and the myocardial cell diameter(MD) were measured after hematoxylin-eosin(HE) staining. The contents of angiotensin Ⅱ(AngⅡ) and angiotensin Ⅱ type 1 receptor(AT1 R) in myocardial tissue were detected by ELISA. The level of Ca~(2+) in myocardial tissue was determined by colorimetry. The protein expression levels of phospholipase C(PLC), inositol triphosphate(IP3), AngⅡ, and AT1 R were assayed by Western blot. Real-time quantitative PCR(qRT-PCR) was employed to determine the mRNA expression levels of β-myosin heavy chain(β-MHC), atrial natriuretic factor(ANF), AngⅡ, and AT1 R. Compared with the model group, Leo decreased the LVSP, LVEDP, HWI, LVWI and MD values, but increased ±dp/dt_(max) of the left ventricle. Meanwhile, it improved the pathological morphology of myocardial tissue, reduced cardiac hypertrophy, edema, and inflammatory cell infiltration, decreased the protein expression levels of PLC, IP3, AngⅡ, AT1 R, as well as the mRNA expression levels of β-MHC, ANF, AngⅡ, AT1 R, c-fos, and c-Myc in myocardial tissue. Leo inhibited AAC-induced cardiac hypertrophy possibly by influencing the RAS system.


Subject(s)
Angiotensin II/metabolism , Animals , Cardiomegaly/genetics , Gallic Acid/analogs & derivatives , Hypertrophy, Left Ventricular/pathology , Myocardium/pathology , Rats
3.
Acta Physiologica Sinica ; (6): 125-133, 2022.
Article in English | WPRIM | ID: wpr-927588

ABSTRACT

Captopril can have nephrotoxic effects, which are largely attributed to accumulated renin and "escaped" angiotensin II (Ang II). Here we test whether angiotensin converting enzyme-1 (ACE1) inhibition damages kidneys via alteration of renal afferent arteriolar responses to Ang II and inflammatory signaling. C57Bl/6 mice were given vehicle or captopril (60 mg/kg per day) for four weeks. Hypertension was obtained by minipump supplying Ang II (400 ng/kg per min) during the second 2 weeks. We assessed kidney histology by periodic acid-Schiff (PAS) and Masson staining, glomerular filtration rate (GFR) by FITC-labeled inulin clearance, and responses to Ang II assessed in afferent arterioles in vitro. Moreover, arteriolar H2O2 and catalase, plasma renin were assayed by commercial kits, and mRNAs of renin receptor, transforming growth factor-β (TGF-β) and cyclooxygenase-2 (COX-2) in the renal cortex, mRNAs of angiotensin receptor-1 (AT1R) and AT2R in the preglomerular arterioles were detected by RT-qPCR. The results showed that, compared to vehicle, mice given captopril showed lowered blood pressure, reduced GFR, increased plasma renin, renal interstitial fibrosis and tubular epithelial vacuolar degeneration, increased expression of mRNAs of renal TGF-β and COX-2, decreased production of H2O2 and increased catalase activity in preglomerular arterioles and enhanced afferent arteriolar Ang II contractions. The latter were blunted by incubation with H2O2. The mRNAs of renal microvascular AT1R and AT2R remained unaffected by captopril. Ang II-infused mice showed increased blood pressure and reduced afferent arteriolar Ang II responses. Administration of captopril to the Ang II-infused mice normalized blood pressure, but not arteriolar Ang II responses. We conclude that inhibition of ACE1 enhances renal microvascular reactivity to Ang II and may enhance important inflammatory pathways.


Subject(s)
Angiotensin II/pharmacology , Animals , Arterioles/metabolism , Captopril/pharmacology , Hydrogen Peroxide/pharmacology , Kidney , Mice
4.
Braz. J. Pharm. Sci. (Online) ; 58: e19922, 2022. tab, graf
Article in English | LILACS | ID: biblio-1384022

ABSTRACT

Angiotensin-II (AgII) is thought to be crucial for tumor growth and progression. Moreover, hydrogen sulfide (H2S) performs a controversial action in cancer pathology. Zofenopril (ZF) is an angiotensin-converting enzyme (ACE) inhibitor with H2S donating properties. Hence, this study aims at investigating the tumor suppressor activity of ZF and elucidating the involved trajectories in Ehrlich's solid tumor (EST)-bearing mice. EST was induced by the intradermal injection of Ehrlich's ascites carcinoma cells into femoral region. All parameters were assessed after 28 days post-inoculation or one-week thereafter. ZF treatment resulted in significant reduction of tumor weights with marked decrease in IL-6 and VEGF levels in serum, and tumor Ag II and CEA contents. Additionally, the administration of ZF downregulated the tumor gene expression of cyclin-D, ACE-1, and Bcl2 and upregulated the proapoptotic gene, BAX. Moreover, ZF increased CBS gene expression, which is a major contributor to cellular H2S production. In addition, ZF was able to reduce the protein expression of PI3K, pAKT, pGSK-3ß, and NFκB. Our study has provided novel insights into the possible mechanisms by which ZF may produce its tumor defeating properties. These intersecting trajectories involve the interference between PI3K/Akt and CBS signaling pathways


Subject(s)
Animals , Male , Mice , Carcinoma, Ehrlich Tumor/pathology , Neoplasms , Angiotensin II/adverse effects , Carcinoma/pathology , Gene Expression , Vascular Endothelial Growth Factor A
5.
Rio de Janeiro; s.n; 2021. xiii, 73 p. ilus.
Thesis in Portuguese | LILACS | ID: biblio-1391765

ABSTRACT

O diabetes mellitus (DM) é um grande problema de saúde pública, que afeta cerca de 463 milhões de pessoas no mundo e pode alcançar 700 milhões de pessoas até 2045. A nefropatia é uma das complicações microvasculares do diabetes e a maior causa de insuficiência renal. Uma vez que a ativação do receptor AT1 pela angiotensina II causa vasoconstrição da artéria aferente, e que o acúmulo de produtos finais de glicação avançada (AGEs) causam glicotoxicidade intracelular de células mesangiais, podocitárias e tubulares, foi avaliado se o tratamento combinado de olmersatana (OLM) e piridoxamina (PYR) é capaz de melhorar a nefropatia diabética quando comparado aos tratamentos isolados. Para isto, o diabetes mellitus experimental foi induzido em 50 camundongos C57BL/6 pela administração de estreptozotocina (50 mg/kg/dia via intraperitoneal por 5 dias). Os animais foram divididos em cinco grupos: controle, diabéticos, diabéticos tratados com OLM (20 mg/Kg/dia), diabéticos tratados com PYR (400 mg/Kg/dia) e diabéticos tratados com OLM e PYR (20 mg/Kg/dia e 400 mg/Kg/dia, respectivamente) Os tratamento durou 16 semanas. Como resultado, os camundongos que receberam STZ desenvolveram hiperglicemia e doença renal, diminuição de peso, poliúria, polidipsia, polifagia, e albuminúria, além de aumento de frutosamina, ferro, uréia e fosfatase alcalina na urina, diminuição da atividade de catalase no rim e aumento de excreção dos AGEs na urina. Histologicamente, houve aumento de área glomerular e do espaço de BowmanO tratamento com OLM atenuou a albuminúria e atenuou o declínio da função renal, uma vez que o OLM melhorou a polidipsia, polifagia, poliúria, marcadores bioquímicos de disfunção renal e parâmetros histológicos, apesar de não apresentar ação sobre a fosfatase alcalina, uréia, ferro, frutosamina e ácido úrico. O tratamento isolado com PYR melhorou a maioria dos parâmetros alterados pela doença, entre eles a ingestão alimentar, ingestão hídrica, volume urinário, creatinina sérica, excreção de albumina na urina, ACR, AGEs no tecido renal e urina, ureia na urina e todos os parâmetros morfológicos analisados, contudo sem efeito sobre a fosfatase alcalina, ferro, frutosamina e ácido úrico. O tratamento combinado (PYR e OLM) melhorou a polifagia, polidipsia e poliúria comparado aos animais diabéticos sem tratamento, entretanto não houve diferença comparado a cada tratamento isolado. Os parâmetros histológicos e bioquímicos (creatinina no soro, albumina na urina, ACR e uréia) também apresentaram melhorara em relação aos animais diabéticos sem tratamento, mas não em relação aos animais em tratamento isolado. Tanto PYR quanto OLM não influenciaram a excreção de AGEs na urina. Esses dados nos levam a concluir que o tratamento combinado não ofereceu efeitos benéficos adicionais quando comparado aos tratamentos isolados, e que o tratamento que mais ofereceu benefícios foi o tratamento isolado com PYR nos parâmetros metabólicos, morfológicos e de função renal. (AU)


Subject(s)
Angiotensin II , Glycation End Products, Advanced , Receptor, Angiotensin, Type 1 , Diabetes Mellitus , Diabetic Nephropathies/diagnosis , Renal Insufficiency
6.
Acta cir. bras ; 36(1): e360105, 2021. graf
Article in English | LILACS | ID: biblio-1152695

ABSTRACT

ABSTRACT Purpose To investigate the relationship between atherosclerotic abdominal aortic aneurysm (AAA) and CXC chemokine receptor type 2 (CXCR2). Methods Mouse AAA model was established by embedding angiotensin-II pump (1000 ng/kg/min) in ApoE-/- mice. Mice were received SB225002, a selective CXCR2 antagonist, for treatment. Blood pressure was recorded, and CXCR2+ macrophages were examined by flow cytometry analysis. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was performed to detect cell apoptosis of abdominal aortic aneurysms. Macrophages were isolated from ApoE-/- mice and treated with Ang II and/or SB225002. Dihydroethidium staining was carried out to determine reactive oxygen species (ROS) activity. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the production of IL-1β and TNF-α. The corresponding gene expressions were measured using real-time polymerase chain reaction (PCR), western blot, and immunohistochemistry staining. Results We found that Ang II activated the expression of CXCR2 in monocytes during the formation of AAA. Inhibition of CXCR2 significantly reduced the size of AAA, attenuated inflammation and phenotypic changes in blood vessels. Ang II-induced macrophages exhibited elevated ROS activity, and elevated levels of 1β and TNF-α, which were then partly abolished by SB225002. Conclusions CXCR2 plays an important role in AAA, suggesting that inhibiting CXCR2 may be a new treatment for AAA.


Subject(s)
Animals , Mice , Aortic Aneurysm, Abdominal/prevention & control , Aortic Aneurysm, Abdominal/drug therapy , Apolipoproteins E/genetics , Angiotensin II , Receptors, Interleukin-8B , Disease Models, Animal , Macrophages , Mice, Inbred C57BL
7.
Chinese Medical Journal ; (24): 2175-2185, 2021.
Article in English | WPRIM | ID: wpr-921109

ABSTRACT

BACKGROUND@#Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis, partially by activating lung fibroblasts. However, how macrophages communicate with lung fibroblasts is largely unexplored. Exosomes can mediate intercellular communication, whereas its role in lung fibrogenesis is unclear. Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis.@*METHODS@#In vivo, bleomycin (BLM)-induced lung fibrosis model was established and macrophages infiltration was examined. The effects of GW4869, an exosomes inhibitor, on lung fibrosis were assessed. Moreover, macrophage exosomes were injected into mice to observe its pro-fibrotic effects. In vitro, exosomes derived from angiotensin II (Ang II)-stimulated macrophages were collected. Then, lung fibroblasts were treated with the exosomes. Twenty-four hours later, protein levels of α-collagen I, angiotensin II type 1 receptor (AT1R), transforming growth factor-β (TGF-β), and phospho-Smad2/3 (p-Smad2/3) in lung fibroblasts were examined. The Student's t test or analysis of variance were used for statistical analysis.@*RESULTS@#In vivo, BLM-treated mice showed enhanced infiltration of macrophages, increased fibrotic alterations, and higher levels of Ang II and AT1R. GW4869 attenuated BLM-induced pulmonary fibrosis. Mice with exosomes injection showed fibrotic features with higher levels of Ang II and AT1R, which was reversed by irbesartan. In vitro, we found that macrophages secreted a great number of exosomes. The exosomes were taken by fibroblasts and resulted in higher levels of AT1R (0.22 ± 0.02 vs. 0.07 ± 0.02, t = 8.66, P = 0.001), TGF-β (0.54 ± 0.05 vs. 0.09 ± 0.06, t = 10.00, P < 0.001), p-Smad2/3 (0.58 ± 0.06 vs. 0.07 ± 0.03, t = 12.86, P < 0.001) and α-collagen I (0.27 ± 0.02 vs. 0.16 ± 0.01, t = 7.01, P = 0.002), and increased Ang II secretion (62.27 ± 7.32 vs. 9.56 ± 1.68, t = 12.16, P < 0.001). Interestingly, Ang II increased the number of macrophage exosomes, and the protein levels of Alix (1.45 ± 0.15 vs. 1.00 ± 0.10, t = 4.32, P = 0.012), AT1R (4.05 ± 0.64 vs. 1.00 ± 0.09, t = 8.17, P = 0.001), and glyceraldehyde-3-phosphate dehydrogenase (2.13 ± 0.36 vs. 1.00 ± 0.10, t = 5.28, P = 0.006) were increased in exosomes secreted by the same number of macrophages, indicating a positive loop between Ang II and exosomes production.@*CONCLUSIONS@#Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.


Subject(s)
Angiotensin II , Animals , Bleomycin/toxicity , Exosomes , Fibroblasts , Lung , Macrophages , Mice , Mice, Inbred C57BL , Pulmonary Fibrosis/chemically induced , Receptor, Angiotensin, Type 1
9.
Article in English | WPRIM | ID: wpr-880634

ABSTRACT

OBJECTIVES@#Silence of SET domain containing lysine methyltransferase 7 (SET7) alleviates myocardial tissue injury caused by ischemia-reperfusion. But the effects of SET7 on angiotensin II (Ang II)-induced myocardial fibroblast proliferation and the collagen synthesis are not clear. The purpose of this study was to explore the effect of SET7 on the proliferation and collagen synthesis of myocardial fibroblasts and its mechanisms.@*METHODS@#Myocardial fibroblasts were isolated and identified by immunofluorescence. Myocardial fibroblasts were randomly divided into 4 groups: a control group (cells were normally cultured), an Ang II group (cells were treated with 100 nmol/L Ang II for 24 h), a siCtrl group (cells were transfected with siRNA control and were then treated with 100 nmol/L Ang II for 24 h), and a siSET7 group (cells were transfected with siRNA SET7 and were then treated with 100 nmol/L Ang II for 24 h). Cell counting kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assay were used to evaluate cell proliferation. Real-time PCR was used to detect the mRNA levels of SET7, collagen I, collagen III, and α-smooth muscle actin (α-SMA). Western blotting was used to detect the protein expression of SET7, collagen I, collagen III, α-SMA, sonic hedgehog (Shh), ptched1 (Ptch1), and glioma-associated oncogene homolog 1 (Gli1).@*RESULTS@#Fluorescence microscopy showed positive vimentin staining, and myocardial fibroblasts were in good condition. As compared to the control group, the mRNA and protein levels of SET7 in the Ang II group were significantly upregulated; cell proliferation rate and EdU fluorescence intensity in the Ang II group were significantly increased; the mRNA and protein levels of collagen I, collagen III, and α-SMA were significantly upregulated (all @*CONCLUSIONS@#Silence of SET7 gene inhibits Ang II-induced proliferation and collagen synthesis of myocardial fibroblasts. Shh signaling pathway may be involved in this process.


Subject(s)
Angiotensin II/pharmacology , Cell Proliferation , Cells, Cultured , Collagen/genetics , Fibroblasts , Hedgehog Proteins
10.
Arq. bras. oftalmol ; 83(4): 318-322, July-Aug. 2020. tab, graf
Article in English | LILACS | ID: biblio-1131605

ABSTRACT

ABSTRACT Purpose: The renin-angiotensin system is involved in the pathogenesis of retinal ischemic conditions and glaucoma. Our objective was to evaluate the renin, angiotensinconverting enzyme 1, and angiotensin-converting enzyme 2 activities in aqueous humor and blood samples of patients with and without primary open-angle glaucoma. Methods: We analyzed samples from 56 participants who underwent ocular surgeries. The patients were divided into two groups: patients with cataract alone (n=28) and patients with cataract and primary open-angle glaucoma (n=28). Venous blood (2 ml) and aqueous humor (150 µl, via paracentesis) samples were collected during phacoemulsification (cataract only) or glaucoma surgery (cataract and primary open-angle glaucoma). The serum and aqueous humor renin, angiotensin-converting enzyme 1, and angiotensin-converting enzyme 2 activities of all patients were evaluated by fluorimetric assays, and results were analyzed by using multivariate regression analysis. Results: Both the aqueous humor renin activity and renin activity aqueous humor/serum ratio were significantly lower in patients with cataract and primary open-angle glaucoma than in patients with cataract only [(mean ± SE): 0.018 ± 0.006 ng/ml/h vs 0.045 ± 0.009 ng/ml/h, p<0.001; 0.05 ± 0.02 vs 0.13 ± 0.05, p=0.025]. Multivariate analyses showed a significant relationship between lower aqueous humor renin activity and primary open-angle glaucoma [coefficient (±SE): -0.029 ± 0.013, p=0.026]. Conclusions: Our results showed that patients with primary open-angle glaucoma had lower aqueous humor renin activity. As timolol eye drops were used by most of the primary open-angle glaucoma patients, we propose that a large sample of washed-out patients should be studied in the future to discriminate the involvement of b-blocker treatment in the aqueous humor renin activity.


RESUMO Objetivo: O sistema renina-angiotensina está envolvido na patogênese das condições isquêmicas retinianas e no glaucoma. Nosso objetivo foi avaliar a atividade da renina, enzima conversora de angiotensina 1 e 2 no humor aquoso, e amostras de sangue de pacientes com e sem glaucoma primário de ângulo aberto. Métodos: Foram analisadas amostras de 56 participantes submetidos à cirurgia ocular. Os pacientes foram divididos em dois grupos: pacientes com catarata apenas (n=28), e pacientes com catarata e glaucoma primário de ângulo aberto (n=28). Amostras de sangue venoso (2ml) e humor aquoso (150 µl, via paracentese) foram coletadas durante a facoemulsificação (apenas catarata) ou cirurgia de glaucoma (catarata e glaucoma primário de ângulo aberto). As atividades sérica do humor aquoso de renina, enzima conversora de angiotensina 1 e enzima conversora de angiotensina 2 de todos os pacientes foram avaliadas por ensaios fluorimétricos, e os resultados foram analisados por regressão multivariada. Resultados: Tanto a atividade da renina no humor aquoso quanto à razão humor aquoso/soro da atividade da renina foram significativamente menores nos pacientes com catarata e glaucoma primário de ângulo aberto do que em pacientes com catarata apenas [(média ± DP): 0,018 ± 0,006 ng/ml/h vs 0,045 ± 0,009 ng/ml/h; p<0,001 e 0,05 ± 0,02 vs 0,13 ± 0,05; p=0,025]. Análises multivariadas mostraram uma releção significativa entre menor atividade de renina no humor aquoso e glaucoma primário de ângulo aberto [coeficiente (±erro padrão): -0,029 ± 0,013; p=0,026]. Conclusões: Como a maioria dos pacientes com glaucoma primário de ângulo aberto usavam o colírio de timolol, estudos futuros envolvendo um maior número de pacientes e retirada prévia do tratamento são necessários para se discriminar o envolvimento do uso de betabloqueadores na atividade da renina no humor aquoso.


Subject(s)
Humans , Aqueous Humor , Cataract , Angiotensin I , Angiotensin II , Glaucoma, Open-Angle , Renin
11.
São Paulo; s.n; s.n; 2020. 107 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-1284427

ABSTRACT

A insuficiência cardíaca (IC) é uma síndrome de elevada morbimortalidade, correspondendo a um grave problema de saúde pública. Uma das abordagens terapêuticas para IC consiste no uso de antagonistas do receptor de angiotensina II do tipo 1 (AT1R), conhecidos como sartanas. Estudos apontam que uma nova classe de compostos, os agonistas enviesados, é capaz de induzir a sinalização da via da ß-arrestina sem ativação da via da proteína G. Essa seletividade funcional é particularmente interessante, pois a via dependente da proteína G é responsável pelo aumento da pressão arterial, morte celular e fibrose tecidual, levando a hipertrofia cardíaca e progressão da IC. No entanto, a via da ß-arrestina está associada com renovação celular e aumento do inotropismo. Além disso, estudos in vivo sugerem que agonistas enviesados poderiam corresponder a uma terapia superior à dos antagonistas convencionais, que bloqueiam ambas as vias. Apesar do potencial terapêutico, esses compostos possuem estrutura peptídica e, por isso, tem sua administração restrita à via intravenosa. A resolução da estrutura cristalográfica do AT1R permitiu estudos de modelagem molecular mais acurados. Tendo isso em mente, nesse trabalho foram propostos agonistas enviesados de natureza não peptídica para o AT1R por meio de técnicas de modelagem molecular e validação das hipóteses levantadas por ensaios in vitro. Foram realizados estudos de dinâmica molecular com o AT1R (PDB ID: 4YAY) em uma bicamada lipídica e ensaios de ancoramento molecular da angiotensina II (AngII) e do ligante enviesado TRV027. As poses de ancoramento molecular selecionadas foram utilizadas em dinâmicas de complexo, que revelaram diferenças entre os sistemas apo (sem nenhum ligante) e holo (com o ligante no sitio de ligação). Nossos resultados sugerem que o TRV027 induz um padrão exclusivo de ligações de hidrogênio e de estrutura secundária, enquanto que a AngII afeta os resíduos do bolso hidrofóbico do sitio de ligação, principalmente a conformação do Trp2536.48. Com base nas simulações, três farmacóforos foram criados e utilizados de maneira complementar em triagens virtuais na base de dados ZINC15, resultando na seleção de cinco compostos. Um desses compostos apresentou afinidade pelo receptor AT1R e, ainda que estudos complementares de ativação de vias especificas sejam necessários para que o composto possa ser classificado como agonista enviesado, já se constitui em molécula potencialmente promissora. Além disso, esses estudos permitiram a proposição de estruturas inéditas que podem vir a ser hits no processo de desenvolvimento de agonistas enviesados para AT1R. Portanto, como continuidade desse trabalho, essas moléculas serão sintetizadas e investigadas quanto à possível interação com o receptor.


Heart Failure (HF) is a common syndrome with high morbimortality, being considered a serious public health problem. One of the therapeutic approaches for HF consists in the use of the sartan class, which are angiotensin II type 1 receptor (AT1R) antagonists. Recent studies have shown that a new class of compounds, known as biased agonists, is able to induce signaling via ß-arrestin without G-protein activation. This functional selectivity is particularly interesting since G-protein dependent signaling is responsible for cell death and cardiac tissue fibrosis, which leads to cardiac muscle hypertophy and HF progression. On the other hand, ß-arrestin signaling is associated with cellular renewal and increased inotropism. In vivo studies suggests that biased agonists could correspond to a superior therapy over conventional angiotensin II type 1 receptor antagonists, which blocks cell signaling as a whole, however their peptidic structure restricts their use to intravenous administration. Moreover, the AT1R crystal structure determination holds great promise for more accurate molecular modeling studies. With that being said, the aim of this work was to plan and develop new non-peptidic biased agonists for ATR1 employing molecular modeling techniques and in vitro tests for hypothesis validation. Molecular dynamics (MD) simulations of the refined AT1R crystal (PDB ID: 4YAY) embedded in a lipid bilayer and molecular docking studies with angiotensin II (AngII) and TRV027 (biased agonist) were conducted. Selected docking poses from both ligands underwent complex MD simulations revealing differences between apo (ligand free) and holo (ligand in the binding site) systems. Our results suggest that TRV027 induces an exclusive hydrogen bond and secondary structure pattern, while AngII affects the hydrophobic pocket conformation, mainly Trp253. Based on the simulations, three pharmacophore models were created and used in virtual screenings in the ZINC15 database, resulting in the selection of five compounds that were tested in vitro. One of the compounds displayed affinity for AT1R and is a promising molecule. Nonetheless, it needs further pathway activation characterization in order to be a classified as a biased agonist. Furthermore, these results have contributed significantly for the proposition of new structures that could be hits with biased agonist activity for AT1R. Thus, for future works, we point out the necessity for synthesis and characterization of this new compounds


Subject(s)
In Vitro Techniques/methods , Angiotensin II/agonists , Diagnosis , Heart Failure/pathology , Ligands , Organization and Administration , Receptors, Angiotensin/analysis , Receptor, Angiotensin, Type 1/analysis , Methods
12.
Braz. j. med. biol. res ; 53(2): e8793, 2020. tab, graf
Article in English | LILACS | ID: biblio-1055493

ABSTRACT

Aliskiren (ALS) is well known for its antihypertensive properties. However, the potential underlying the molecular mechanism and the anti-hypertrophic effect of ALS have not yet been fully elucidated. The aim of the present study was to investigate the role of ALS in mammalian target of rapamycin (mTOR) and apoptosis signaling using in vivo and in vitro models of cardiac hypertrophy. A rat model of cardiac hypertrophy was induced by isoproterenol treatment (5 mg·kg-1·day-1) for 4 weeks, with or without ALS treatment at 20 mg·kg-1·day-1. The expression of hypertrophic, fibrotic, and apoptotic markers was determined by RT-qPCR. The protein expression of apoptotic markers mTOR and p-mTOR was assessed by western blot analysis. The proliferation of H9C2 cells was monitored using the MTS assay. Cell apoptosis was analyzed using flow cytometry. In vivo, isoproterenol-treated rats exhibited worse cardiac function, whereas ALS treatment reversed these dysfunctions, which were associated with changes in p-mTOR, Bcl-2, Bax, and cleaved caspase-3 expression, as well as the number of apoptotic cells. In vitro, H9C2 cardiomyocyte viability was significantly inhibited and cardiac hypertrophy was induced by Ang II administration, but ALS reversed Ang II-induced H9C2 cardiomyocyte hypertrophy and death. Furthermore, Ang II triggered the activation of the mTOR and apoptosis pathways in hypertrophic cardiomyocytes that were inhibited by ALS treatment. These results indicated that ALS alleviated cardiac hypertrophy through inhibition of the mTOR and apoptosis pathways in cardiomyocytes.


Subject(s)
Animals , Male , Rats , Apoptosis/drug effects , Cardiomegaly/prevention & control , TOR Serine-Threonine Kinases/metabolism , Fumarates/administration & dosage , Amides/administration & dosage , Fibrosis/chemically induced , Fibrosis/prevention & control , Angiotensin II/pharmacology , Signal Transduction/drug effects , Blotting, Western , Rats, Sprague-Dawley , Cardiomegaly/chemically induced , Cardiomegaly/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Disease Models, Animal , TOR Serine-Threonine Kinases/drug effects , Flow Cytometry , Isoproterenol/pharmacology
13.
Chinese Journal of Cardiology ; (12): 329-335, 2020.
Article in Chinese | WPRIM | ID: wpr-941113

ABSTRACT

Objective: To investigate if microRNA (miR) -23a knockdown could attenuate angiotensin Ⅱ(AngⅡ) induced cardiac hypertrophy by activating phosphatase and tensin homolog deleted on chromosome ten(PTEN) and AMP-activated protein kinase(AMPK) pathway. Methods: Rat H9c2 cells were cultured in DMEM high glucose medium and put in 5% CO(2) incubator at 37 ℃(normal group). After 48 hours of culture, H9c2 cells were stimulated with 10 nmol/L AngⅡ to establish cell hypertrophy model (AngⅡgroup). The H9c2 cells were inoculated in a 6-well cell culture plate and cultured in an incubator at 37 ℃. When the confluence degree of cell growth was about 70%, the cells were transfected with different reagents, and 24 hours after transfection, 10 nmol/L AngⅡ was used to interfere with the cells. The H9c2 cells were divided into different groups according to the reagents, namely AngⅡ+anti-miR group(transfected with miR-23a inhibitor), Ang Ⅱ+NC group(transfected with miR-23a inhibitor negative control), Ang Ⅱ+anti-miR+si-PTEN group(cotransfected with miR-23a inhibitor and PTEN small interference RNA(siRNA)), and AngⅡ+anti-miR+si-NC group(cotransfected with miR-23a inhibitor and PTEN siRNA negative control). The surface area of single cell was measured by Image J software.The mRNA expression levels of α-actin 1 (ACTA1) and β-myosin heavy chain (β-MHC) and miR-23a were detected by quantitative real-time PCR(qRT-PCR). The expression levels of PTEN and AMPK signal pathway related proteins were detected by Western blot. In order to verify whether miR-23a targets PTEN gene, double luciferase reporter gene experiment was performed. The luciferase reporter gene vector recombinant plasmids of wild type pGL-WT-PTEN and mutant pGL-MUT-PTEN were constructed and prepared after normal sequencing. H9c2 cells was inoculated into 24-well cell culture plate and cultured overnight in 37 ℃ incubator. The cells were co-transfected with miR-23a mimic or miR-23a mimic negative control and wild type or mutant reporter gene recombinant plasmid. Forty-eight hours after transfection, firefly luciferase activity and sea kidney luciferase activity were measured, and the ratio of them was recorded as relative luciferase activity. Results: Compared with the normal group, the cell surface area, the mRNA expression levels of ACTA1, β-MHC and miR-23a were significantly higher, while the protein expression levels of PTEN and p-AMPK were significantly lower in the Ang Ⅱ group(all P<0.05). The results of double luciferase reporter gene assay showed that the relative luciferase activity of cells co-transfected with miR-23a mimic and wild-type reporter gene recombinant plasmid was lower than that of miR-23a mimic negative control (P<0.05), and PTEN served as the target gene of miR-23a. In AngⅡ+anti-miR group the mRNA expression levels of miR-23a, ACTA1 and β-MHC were lower, and the cell surface area was smaller, while the protein expression levels of PTEN and p-AMPK were higher than that in AngⅡ group and AngⅡ+NC group(all P<0.05). Compared with AngⅡ+anti-miR group, the cell surface area was bigger, the expression of ACTA1 and β-MHC mRNA was up-regulated, and the protein expression levels of PTEN and p-AMPK were down-regulated in Ang Ⅱ+anti-miR+si-PTEN group(all P<0.05). Conclusion: Inhibition of miR-23a can attenuate Ang Ⅱ-induced hypertrophy in H9c2 cells through targeting PTEN and activating AMPK signaling pathway.


Subject(s)
AMP-Activated Protein Kinases , Angiotensin II , Animals , Cardiomegaly , Cell Line , Cell Proliferation , MicroRNAs/genetics , PTEN Phosphohydrolase , Rats , Signal Transduction
14.
Braz. J. Pharm. Sci. (Online) ; 56: e18560, 2020. graf
Article in English | LILACS | ID: biblio-1364408

ABSTRACT

The Gαq-RGS2 loop activator, 1-(5-chloro-2-hydroxyphenyl)-3-(4-(trifluoromethyl)-phenyl)-1H-1,2,4-triazol-5(4H)-one has demonstrated Gαq signaling inhibitor activity. Therefore, we aimed to study the effect of Gαq-RGS2 loop activator on isolated heart and aorta of normal rats. Heart and aorta were isolated from the sacrificed rats (n=6) and mounted on the langendroff's and organ bath assembly, respectively. The effect of various receptor-dependent (acetylcholine, angiotensin II and adrenaline) and independent (calcium chloride and sodium nitroprusside) agonists in absence and presence of Gαq-RGS2 loop activator on left ventricular systolic pressure (LVSP) and the contractile responseswere evaluated in isolated heart and aorta, respectively. Gαq-RGS2 loop activator (100 µM) significantly attenuated the adrenaline (p<0.001,) and angiotensin II (p<0.001) induced increase in LVSP in isolated heart and contractile response of adrenaline (p<0.01) and angiotensin II (p<0.01) in the aorta. However, effect calcium chloride did not significantly alter by Gαq-RGS2 loop activator. The effect of acetylcholinewas significantly (p<0.01, p<0.05) increased by Gαq-RGS2 loop activator in isolated heart and aorta. The effect of sodium nitroprusside significantly (p<0.01) potentiated by Gαq-RGS2 loop activator (100 µM) in isolated heart while it did not significantly alters in the aorta. Ultimately, the Gαq-RGS2 loop activator modulated the action of receptor-dependent agonists in isolated heart and aorta


Subject(s)
Animals , Male , Rats , Aorta/pathology , Heart/anatomy & histology , Blood Pressure , Angiotensin II , Cardiovascular Diseases/pathology , Acetylcholine/classification
15.
Rev. ecuat. pediatr ; 20(2): 43-46, diciembre 2019.
Article in Spanish | LILACS | ID: biblio-1116487

ABSTRACT

Los Inhibidores de la enzima convertidora de angiotensina II (IECAs) y antagonistas de los receptores de angiotensina II (ARA II) son drogas usadas comúnmente en el manejo de hipertensión arterial, sin embargo, su uso en el embarazo está asociado con toxicidad fetal.1, 2 La acción de la angiotensina II requiere su unión a dos receptores; AT1, involucrado en el control de la tensión arterial y AT2, probablemente encargado del crecimiento fetal. 2 La angiotensina II es esencial en la hemodinamia sistémica y la filtración glomerular fetal y neonatal. La disminución de la perfusión placentaria por efecto hipotensor en el bloqueo del sistema renina angiotensina aldosterona materno puede determinar hipotensión fetal sistémica, disminución de la filtración glomerular, oligoamnios e insuficiencia renal, anormalidades tubulares, hipoplasia craneal y alto riesgo de muerte perinatal. 2 Reportamos el caso de prematuro de 30 semanas con oligohidramnios severo y exposición materna a olmesartan. Al nacimiento presentó dificultad respiratoria; imposibilidad de mantener una adecuada tensión arterial a pesar de los esfuerzos para conseguir mejorar su tono vascular; anuria sin respuesta a diuréticos; alteraciones craneales; alteraciones metabólicas severas con consecuencias fatales. El tratamiento de hipertensión materna con inhibidores de la enzima convertidora de angiotensina II y los antagonistas de los receptores de angiotensina II está asociada con toxicidad fetal por lo que su uso debe ser evitado durante el embarazo.


Angiotensin II converting enzyme (ACE) inhibitors and angiotensin II receptor antagonists (ARBs) are drugs for general use in the management of arterial hypertension, however their use in gestational hypertension is related to the Fetal toxicity. 1, 2 The action of angiotensin II requires its binding to two receptors; AT1, involved in the control of blood pressure and AT2, probably responsible for fetal growth.2 Angiotensin II is essential in systemic hemodynamics and fetal and neonatal glomerular filtration. The decrease in placental perfusion due to hypotensive effect in the blockade of the maternal rennin angiotensin aldosterone system can determine systemic fetal hypotension, decreased glomerular filtration, oligohydramnios and renal insufficiency, tubular abnormalities, cranial hypoplasia and high risk of perinatal death. 2 We report the case of prematurity of 30 weeks with a history of severe oligohydramnios and maternal exposure to olmesartan. At birth the patient presented in particular respiratory distress; inability to maintain adequate blood pressure despite efforts to improve your vascular tone; anuria without response to diuretics; cranial alterations; metabolic alterations with fatal consequences. The treatment of maternal hypertension with inhibitors of the angiotensin II convective enzyme and angiotensin II receptor antagonists is associated with fetal toxicity and should therefore be avoided during pregnancy


Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Oligohydramnios , Premature Birth , Renal Insufficiency , Angiotensin II , Maternal Exposure , Hypertension, Pregnancy-Induced , Fetal Development , Toxicity , Hypotension
16.
J. pediatr. (Rio J.) ; 95(3): 328-333, May-June 2019. graf
Article in English | LILACS | ID: biblio-1012600

ABSTRACT

Abstract Objective: Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end‐stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve. Methods: Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme‐linked immunosorbent assay. Results: Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang‐(1‐7) and angiotensin‐converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls. Conclusions: Increased urinary levels of angiotensin‐converting enzyme 2 and of Ang‐(1‐7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve.


Resumo Objetivo: A válvula de uretra posterior é a obstrução do trato urinário inferior mais comum em crianças do sexo masculino. Uma alta porcentagem de pacientes com válvula de uretra posterior evolui para doença renal em estágio final. Estudos anteriores mostraram que citocinas, quimiocinas e componentes do sistema renina-angiotensina contribuem para o dano renal em uropatias obstrutivas. Recentemente, descobrimos que amostras de urina de fetos com válvula de uretra posterior tinham níveis aumentados de moléculas inflamatórias. O objetivo deste estudo foi medir as moléculas de renina-angiotensina e investigar sua correlação com marcadores inflamatórios previamente detectados nas mesmas amostras de urina de fetos com válvula de uretra posterior. Métodos: Amostras de urina de 24 fetos com válvula de uretra posterior foram coletadas e comparadas com amostras de urina de 22 recém-nascidos saudáveis de mesma idade gestacional (controles). Os níveis dos componentes de SRA foram medidos por ensaio de imunoabsorção enzimática. Resultados: Os fetos com válvula de uretra posterior apresentaram níveis urinários aumentados de angiotensina (Ang) I, Ang-(1-7) e enzima conversora de angiotensina 2 em comparação com os controles. Os níveis de enzima conversora de angiotensina eram significativamente menores e os níveis de Ang II eram semelhantes nos fetos com válvula de uretra posterior em comparação com os controles. Conclusões: O aumento dos níveis urinários de enzima conversora de angiotensina 2 e de Ang-(1-7) em fetos com válvula de uretra posterior poderia representar uma resposta regulatória ao intenso processo inflamatório desencadeado pela válvula de uretra posterior.


Subject(s)
Humans , Male , Female , Pregnancy , Infant, Newborn , Peptide Fragments/urine , Urethra/abnormalities , Urethral Diseases/urine , Angiotensin I/urine , Angiotensin II/urine , Peptidyl-Dipeptidase A/urine , Fetus/abnormalities , Urethra/embryology , Urethral Diseases/diagnosis , Urethral Diseases/embryology , Biomarkers/urine , Case-Control Studies , Immunosorbent Techniques
17.
Braz. j. med. biol. res ; 52(1): e7914, 2019. graf
Article in English | LILACS | ID: biblio-974273

ABSTRACT

Yes-associated protein (YAP) is an important regulator of cellular proliferation and transdifferentiation. However, little is known about the mechanisms underlying myofibroblast transdifferentiation in dilated cardiomyopathy (DCM). We investigated the role of YAP in the pathological process of cardiac matrix remodeling. A classic model of DCM was established in BALB/c mice by immunization with porcine cardiac myosin. Cardiac fibroblasts were isolated from neonatal Sprague-Dawley rats by density gradient centrifugation. The expression levels of α-smooth muscle actin (α-SMA) and collagen volume fraction (CVF) were significantly increased in DCM mice. Angiotensin II (Ang II)-mediated YAP activation promoted the proliferation and transdifferentiation of neonatal rat cardiac fibroblasts, and this effect was significantly suppressed in the shRNA YAP + Ang II group compared with the shRNA Control + Ang II group in vitro (2.98±0.34 ×105 vs 5.52±0.82 ×105, P<0.01). Inhibition of endogenous Ang II-stimulated YAP improved the cardiac function by targeting myofibroblast transdifferentiation to attenuate matrix remodeling in vivo. In the valsartan group, left ventricular ejection fraction and fractional shortening were significantly increased compared with the DCM group (52.72±5.51% vs 44.46±3.01%, P<0.05; 34.84±3.85% vs 26.65±3.12%, P<0.01). Our study demonstrated that YAP was a regulator of cardiac myofibroblast differentiation, and regulation of YAP signaling pathway contributed to improve cardiac function of DCM mice, possibly in part by decreasing myofibroblast transdifferentiation to inhibit matrix remodeling.


Subject(s)
Animals , Male , Rats , Angiotensin II/pharmacology , Cardiomyopathy, Dilated/physiopathology , Adaptor Proteins, Signal Transducing/drug effects , Cell Transdifferentiation/drug effects , Myofibroblasts/drug effects , Phosphoproteins/antagonists & inhibitors , Phosphoproteins/physiology , Swine , Echocardiography , Cardiomyopathy, Dilated/pathology , Cell Differentiation , Blotting, Western , Rats, Sprague-Dawley , Cell Cycle Proteins , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/physiology , Disease Models, Animal , Myofibroblasts/physiology , Mice, Inbred BALB C , Microscopy, Fluorescence
18.
Article in English | WPRIM | ID: wpr-764077

ABSTRACT

BACKGROUND AND OBJECTIVES: Human amniotic fluid-derived mesenchymal stem cells (AF-MSCs) may be a valuable source for cardiovascular tissue engineering and cell therapy. The aim of this study is to verify angiotensin II and transforming growth factor-beta 1 (TGF-β1) as potential cardiomyogenic differentiation inducers of AF-MSCs. METHODS AND RESULTS: AF-MSCs were obtained from amniocentesis samples from second-trimester pregnant women, isolated and characterized by the expression of cell surface markers (CD44, CD90, CD105 positive; CD34 negative) and pluripotency genes (OCT4, SOX2, NANOG, REX1). Cardiomyogenic differentiation was induced using different concentrations of angiotensin II and TGF-β1. Successful initiation of differentiation was confirmed by alterations in cell morphology, upregulation of cardiac genes-markers NKX2-5, TBX5, GATA4, MYH6, TNNT2, DES and main cardiac ion channels genes (sodium, calcium, potassium) as determined by RT-qPCR. Western blot and immunofluorescence analysis revealed the increased expression of Connexin43, the main component of gap junctions, and Nkx2.5, the early cardiac transcription factor. Induced AF-MSCs switched their phenotype towards more energetic and started utilizing oxidative phosphorylation more than glycolysis for energy production as assessed using Agilent Seahorse XF analyzer. The immune analysis of chromatin-modifying enzymes DNMT1, HDAC1/2 and Polycomb repressive complex 1 and 2 (PRC1/2) proteins BMI1, EZH2 and SUZ12 as well as of modified histones H3 and H4 indicated global chromatin remodeling during the induced differentiation. CONCLUSIONS: Angiotensin II and TGF-β1 are efficient cardiomyogenic inducers of human AF-MSCs; they initiate alterations at the gene and protein expression, metabolic and epigenetic levels in stem cells leading towards cardiomyocyte-like phenotype formation.


Subject(s)
Amniocentesis , Amniotic Fluid , Angiotensin II , Angiotensins , Blotting, Western , Calcium , Cell Differentiation , Cell- and Tissue-Based Therapy , Chromatin , Chromatin Assembly and Disassembly , Connexin 43 , Epigenomics , Female , Fluorescent Antibody Technique , Gap Junctions , Glycolysis , Histones , Humans , Ion Channels , Mesenchymal Stem Cells , Muscle Cells , Oxidative Phosphorylation , Phenotype , Polycomb Repressive Complex 1 , Pregnant Women , Smegmamorpha , Stem Cells , Tissue Engineering , Transcription Factors , Up-Regulation
19.
Acta Physiologica Sinica ; (6): 187-195, 2019.
Article in English | WPRIM | ID: wpr-777197

ABSTRACT

Renin-angiotensin system (RAS) is involved in the regulation of vascular smooth muscle cell (VSMC) tension. Angiotensin II (Ang II) as the main effector molecule of RAS can increase the intracellular Ca concentration and cause VSMCs contraction by activating angiotensin II type 1 receptor (AT1R). The large-conductance Ca- and voltage-activated potassium (BK) channel is an essential potassium channel in VSMCs, playing an important role in maintaining membrane potential and intracellular potassium-calcium balance. The BK channel in VSMCs mainly consists of α and β1 subunits. Functional BKα subunits contain voltage-sensors and Ca binding sites. Hence, increase in the membrane potential or intracellular Ca concentration can trigger the opening of the BK channel by mediating transient K outward current in a negative regulatory manner. However, increasing evidence has shown that although Ang II can raise the intracellular Ca concentration, it also inhibits the expression and function of the BK channel by activating the PKC pathway, internalizing AT1R-BKα heterodimer, or dissociating α and β1 subunits. Under some specific conditions, Ang II can also activate the BK channel, but the underlying mechanism remains unknown. In this review, we summarize the potential mechanisms underlying the inhibitory or activating effect of Ang II on the BK channel, hoping that it could provide a theoretical basis for improving intracellular ion imbalance.


Subject(s)
Angiotensin II , Physiology , Calcium , Physiology , Humans , Large-Conductance Calcium-Activated Potassium Channels , Physiology , Muscle, Smooth, Vascular , Cell Biology , Myocytes, Smooth Muscle , Physiology , Renin-Angiotensin System
20.
Article in Chinese | WPRIM | ID: wpr-774511

ABSTRACT

This paper was aimed to investigate the inhibitory effect of aconitine(AC) on angiotensin Ⅱ(Ang Ⅱ)-induced H9 c2 cell hypertrophy and explore its mechanism of action. The model of hypertrophy was induced by Ang Ⅱ(1×10-6 mol·L-1),and cardiomyocytes were incubated with different concentrations of AC. Western blot was used to quantify the protein expression levels of atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),β-myosin heavy chain(β-MHC),and α-smooth muscle actin(α-SMA). Real-time quantitative PCR(qRT-PCR) was used to quantify the mRNA expression levels of cardiac hypertrophic markers ANP,BNP and β-MHC. In addition,the fluorescence intensity of the F-actin marker,an important component of myofibrils,was detected by using laser confocal microscope. AC could significantly reverse the increase of total protein content in H9 c2 cells induced by Ang Ⅱ; qRT-PCR results showed that AC could significantly inhibit the ANP,BNP and β-MHC mRNA up-regulation induced by AngⅡ. Western blot results showed that AC could significantly inhibit the ANP,BNP and β-MHC protein up-regulation induced by AngⅡ. In addition,F-actin expression induced by Ang Ⅱ could be inhibited by AC,and multiple indicators of cardiomyocyte hypertrophy induced by Ang Ⅱ could be down-regulated,indicating that AC may inhibit cardiac hypertrophy by inhibiting the expression of hypertrophic factors,providing new clues for exploring the cardiovascular protection of AC.


Subject(s)
Aconitine , Pharmacology , Actins , Metabolism , Angiotensin II , Atrial Natriuretic Factor , Metabolism , Cardiac Myosins , Metabolism , Cardiomegaly , Cells, Cultured , Humans , Hypertrophy , Myocytes, Cardiac , Myosin Heavy Chains , Metabolism , Natriuretic Peptide, Brain , Metabolism
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