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Ageing has been associated with comorbidities, systemic low-grade of inflammation, and immunosenescence. Hypertension is the most common morbidity and anti-hypertensives are used for more than 50%. Angiotensin-converting enzyme 1 inhibitors (ACEi) and angiotensin II receptor blockers (ARB) control blood pressure but also seem to play a role in comorbidities such as Alzheimer's disease, sarcopenia and cancer. The impact of anti-hypertensives in comorbidities is due to the expression of renin-angiotensin system (RAS) in several tissues and body fluids. Angiotensin-converting enzyme 1 (ACE1) has been linked to oxidative stress, metabolism, and inflammation. The levels and activity of ACE1 are under genetic control and polymorphisms have been correlated with susceptibility to Alzheimer's disease. In addition, some results found that ACEi and ARB users present delayed cognitive decline and reduced risk of dementia. Regarding to sarcopenia, RAS has been linked to the catabolic and anabolic pathways for muscle mass maintenance. In some studies, older adults using ACEi were highly benefited by exercise training. In cancer, RAS and its products have been shown to play a role since their inhibition in animal models modulates tumor microenvironment and improves the delivery of chemotherapy drugs. Clinically, the incidence of colorectal cancer is reduced in patients using ACEi and ARB. During the pandemic COVID-19 it was found that ACE2 receptor plays a role in the entry of SARS-CoV-2 into the host cell. ACE1 genotypes have been linked to an increased risk for COVID-19 and severe disease. In some studies COVID-19 patients taking ARB or ACEi presented better outcome.

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BACKGROUND: Our previous studies showed increased angiotensin I-converting enzyme (ACE) activity in chronic schizophrenia (SCZ) patients compared to healthy control (HC) volunteers, and the relevance of combining ACE genotype and activity for predicting SCZ was suggested. METHODS: ACE activity was measured in plasma of ACE insertion/deletion (I/D) genotyped HC volunteers (N = 53) and antipsychotic-naïve first-episode psychosis (FEP) patients (N = 45), assessed at baseline (FEB-B) and also after 2-months (FEP-2M) of treatment with the atypical antipsychotic risperidone. RESULTS: ACE activity measurements showed significant differences among HC, FEP-B and FEP-2M groups (F = 5.356, df = 2, p = 0.005), as well as between HC and FEP-2M (post-hoc Tukey's multiple comparisons test, p = 0.004). No correlation was observed for ACE activity increases and symptom severity reductions in FEP as assessed by total PANSS (r = -0.131, p = 0.434). FEP subgrouped by ACE I/D genotype showed significant ACE activity increases, mainly in the DD genotype subgroup. No correlation between ACE activity and age was observed in FEP or HC groups separately (r = 0.210, p = 0.392), but ACE activity levels differences observed between these groups were influenced by age. CONCLUSIONS: The importance of measuring the ACE activity in blood plasma, associated to ACE I/D genotyping to support the follow-up of FEP patients did not show correlation with general symptoms amelioration in the present study. However, new insights into the influence of age and I/D genotype for ACE activity changes in FEP individuals upon treatment was demonstrated.

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The two-domain dipeptidylcarboxypeptidase Angiotensin-I-converting enzyme (EC 3.4.15.1; ACE) plays an important physiological role in blood pressure regulation via the reninangiotensin and kallikrein-kinin systems by converting angiotensin I to the potent vasoconstrictor angiotensin II, and by cleaving a number of other substrates including the vasodilator bradykinin and the anti-inflammatory peptide N-acetyl-SDKP. Therefore, the design of ACE inhibitors is within the priorities of modern medical sciences for treating hypertension, heart failures, myocardial infarction, and other related diseases. Despite the success of ACE inhibitors for the treatment of hypertension and congestive heart failure, they have some adverse effects, which could be attenuated by selective domain inhibition. Crystal structures of both ACE domains (nACE and cACE) reported over the last decades could facilitate the rational drug design of selective inhibitors. In this review, we refer to the history of the discovery of ACE inhibitors, which has been strongly related to the development of molecular modeling methods. We stated that the design of novel selective ACE inhibitors is a challenge for current researchers which requires a thorough understanding of the structure of both ACE domains and the help of molecular modeling methodologies. Finally, we performed a theoretical design of potential selective derivatives of trandolaprilat, a drug approved to treat critical conditions of hypertension, to illustrate how to use molecular modeling methods such as de novo design, docking, Molecular Dynamics (MD) simulations, and free energy calculations for creating novel potential drugs with specific interactions inside nACE and cACE binding sites.

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Snakebite accidents are a serious public health problem neglected in tropical countries. In Brazil, the Northern Region has the largest number of cases and snakes from Lachesis genus are responsible for the most serious accidents and the highest number of deaths. Victims of Lachesis envenoming have bite site damage, bleeding and, in severe cases, hypotension. Proteomic and transcriptomic studies report the presence of bradykinin potentiating peptide (BPPs) in L. muta venom, however, there are no data in the literature describing their purifications and identifications. The objective of this work is to identify and characterize angiotensin-converting enzyme inhibitors in the low molecular weight portion of Lachesis muta venom. For this lyophilized L. muta venom was dissolved in ammonium acetate buffer and filtered by centrifugation for size fractionating, using a 10 kDa centrifugal filter unit. The low molecular weight fraction was then chromatographed by RP-HPLC using a C18 column. Twelve fractions were collected and four were tested in fluorimetric assays using ACE as an enzyme and Abz-FRK(Dnp)P-OH as substrate. These fractions present peaks with retention time similar to the peaks that contained BPPs of other snake venoms. In addition, four fractions presented 100% inhibition of the catalytic activity of ACE over the FRET substrate. Based on these results, and due to other data in the literature describing the presence of BPPs in L. muta venom, is possible that it may contain BPPs. For confirmation of this hypothesis, the next step will be to perform analysis by mass spectrometry aiming to determine the primary sequences of the peptides present in each fraction.

Os acidentes ofídicos são um grave problema de saúde pública negligenciado em países tropicais. No Brasil, a Região Norte apresenta o maior número de casos e as serpentes do gênero Lachesis são responsáveis pelos acidentes mais graves e com maior número de óbitos. Vítimas do envenenamento por Lachesis apresentam danos no local da picada, hemorragias e em casos graves apresentam hipotensão arterial. Estudos proteômicos e trancriptômicos descrevem a presença de peptídeos potenciadores de bradicinina (BPPs) no veneno de Lachesis muta, porém não há dados na literatura descrevendo o isolamento e/ou suas identificações. O objetivo deste trabalho é identificar e caracterizar inibidores da enzima conversora de angiotensina (ECA) na porção de baixa massa molecular do veneno de Lachesis muta. Para isso o veneno liofilizado de Lachesis muta foi dissolvido em tampão acetato de amônio e filtrado por centrifugação para o fracionamento de tamanho, usando uma membrana de corte de 10 kDa. A porção de baixa massa molecular foi fracionada por RP-HPLC usando uma coluna C-18. Doze frações foram coletadas e quatro foram testadas em ensaios fluorimétricos utilizando a ECA como enzima e o Abz-FRK(Dnp)P-OH como substrato. Das quatro frações selecionadas, duas se destacaram devido à alta intensidade dos picos, um em 13,65 minutos de retenção e outro em 14 minutos de retenção, com 44% e 45% concentração de solução B, respectivamente. As frações de interesse apresentam picos eluídos nos mesmos tempos de retenção que os BPPs de outros venenos de serpentes, sugerindo, juntamente com dados da literatura, que eles podem conter BPPs semelhantes. As quatro frações inibiram em 100% a atividade catalítica da ECA sobre o substrato Abz-FRK(Dnp)P-OH. Por essas razões e devido outros dados na literatura descreverem a presença BPPs no veneno de L. muta, acreditamos que as quatro frações selecionadas contenham BPPs. Para a confirmação o próximo passo será realizar a análise por espectrometria de massas.

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This review is focused on the state-of-art of peptides with inhibitory activity towards angiotensin I-converting enzyme (ACE) - thus, with anti-hypertensive potential - derived from enzymatic hydrolysis of caseins. Firstly, molecular characteristics of caseins relevant to a better understanding of this subject were concisely commented. Next, a brief description of the pathophysiology of hypertension was explained, focusing on the ACE role in regulation of blood pressure in human body. Then, casein-derived peptides with ACE inhibitory capacity were specifically addressed. The main in vitro and in vivo bioassays often reported in literature to assess the anti-hypertensive potential of peptides were presented, illustrated with recently published studies, and discussed in terms of advantages and limitations of both approaches. Characteristics related to amino acid composition and sequence of peptides with high ACE-inhibitory potential were also commented. Process parameters of enzymatic hydrolysis (types and origins of casein substrates, types of enzymes, pH, temperature, and times of reactions) were discussed. Patents dealing with casein-derived anti-hypertensive peptides were examined not only in terms of amino acid sequences, but also regarding their novelty claims in hydrolysis process parameters. Finally, some trends, challenges, and opportunities inferred from this literature analysis were commented, emphasizing the importance of this research topic in food products development.

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Cryptids are peptides with bioactive function that are hidden in other proteins, having similar or even different function from these mother proteins. The objective of this work is to analyze the generation of these cryptides from the hydrolysis of hemoglobin, which already has active peptides described as hemocidin, hemorphine and hemopressin, and to analyze their interaction with the enzymes ACE (Angiotensin Converting Enzyme) and Renin that are part of the system Renin- Angiotensin which is fundamental for cardio circulatory regulation. Hydrolysis of the hemoglobin was performed by trypsin, and the material was analyzed in SDS-Page and fractionated in High Pressure Liquid Chromatography. The mass of the peptides generated in LC-MS and in silico was determined. Preliminary tests were performed with ACE and the fractions, with results above 60% inhibition. The tests were redone in a fluorimetric assay again showing results above 60% inhibition in 4 fractions. The fluorimetric test was also used with the enzyme renin, with results around 20% inhibition. These same fractions were tested for MTT in fibroblast cell culture and no toxicity or proliferation was observed.

Os criptídeos são peptídeos com função bioativa que se encontram ocultos em outras proteínas, tendo função semelhante ou até distinta dessas proteínas-mãe. O objetivo deste trabalho é analisar a geração destes criptídeos a partir da hidrólise de hemoglobina, que já possui peptídeos ativos descritos como a hemocidina, hemorfina e hemopressina, e analisar a interação deles com as enzimas ECA (Enzima Conversora de Angiotensina) e Renina que fazem parte do sistema Renina- Angiotensina que é fundamental na regulação cardiocirculatória. Para isso foi realizada uma hidrólise da hemoglobina por tripsina, sendo esse material analisado em SDS-PAGE e fracionado em Cromatografia Líquida de Alta Pressão. Foi determinada a massa dos peptídeos gerados em LC-MS e in silico. Foram realizados testes preliminares com a ECA e as frações, tendo resultados acima de 60% de inibição. Os testes foram refeitos em ensaio fluorimétrico apresentando novamente resultados acima de 60% de inibição diante 4 frações. O teste fluorimétrico foi usado também com a enzima renina, apresentando resultados em torno de 20% de inibição. Essas mesmas frações foram testadas por MTT em cultura celular de fibroblastos e não foi notada toxicidade ou proliferação.

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This study aimed to analyze the angiotensin-converting enzyme (ACE-I/D) allelic and genotypic frequencies in Brazilian soccer players of different ages. The study group comprised 353 players from first-division clubs in the under (U)-14, U-15, U-17, U-20, and professional categories. The allelic and genotypic frequencies did not differ significantly in any of the categories between the group of players and the control group. This was the first study of ACE-I/D polymorphism in Brazilian soccer players.

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BACKGROUND: The snakes from the Bitis genus are some of the most medically important venomous snakes in sub Saharan Africa, however little is known about the composition and effects of these snake venom peptides. Considering that the victims with Bitis genus snakes have exacerbate hypotension and cardiovascular disorders, we investigated here the presence of angiotensin-converting enzyme modulators on four different species of venoms. METHODS: The peptide fractions from Bitis gabonica gabonica, Bitis nasicornis, Bitis gabonica rhinoceros and Bitis arietans which showed inhibitory activity on angiotensin-converting enzyme were subjected to mass spectrometry analysis. Eight proline-rich peptides were synthetized and their potencies were evaluated in vitro and in vivo. RESULTS: The MS analysis resulted in over 150 sequences, out of which 32 are new proline-rich oligopeptides, and eight were selected for syntheses. For some peptides, inhibition assays showed inhibitory potentials of cleavage of angiotensin I ten times greater when compared to bradykinin. In vivo tests showed that all peptides decreased mean arterial pressure, followed by tachycardia in 6 out of 8 of the tests. CONCLUSION: We describe here some new and already known proline-rich peptides, also known as bradykinin-potentiating peptides. Four synthetic peptides indicated a preferential inhibition of angiotensin-converting enzyme C-domain. In vivo studies show that the proline-rich oligopeptides are hypotensive molecules. GENERAL SIGNIFICANCE: Although proline-rich oligopeptides are known molecules, we present here 32 new sequences that are inhibitors of the angiotensin-converting enzyme and consistent with the symptoms of the victims of Bitis spp, who display severe hypotension.

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Introducción: la preeclampsia constituye una causa importante de morbimortalidad materna y perinatal en el mundo. Su etiopatogenia es aún un enigma; sin embargo, los avances en genómica y proteómica prometen la identificación temprana de la enfermedad o del riesgo de padecerla. Objetivo: hacer una reflexión sobre los avances más promisorios de la genómica y proteómica, en el tamizaje y/o predicción de la preeclampsia. Conclusiones: dos polimorfismos funcionales, uno en el gen ACE (I/D) y otro en el gen COMT (Val158Met), poseen los resultados más promisorios para cumplir con el objetivo de identificar genéticamente a las mujeres con mayor riesgo de desarrollar preeclampsia durante un embarazo. Por su parte, la proteómica ha identificado a la SERPINA-1 como un biomarcador útil para detectar en la orina de las embarazadas que estén desarrollando la preeclampsia, con al menos 10 semanas de antelación a las manifestaciones clínicas de la misma y la necesidad de finalizar el embarazo. En conjunto, estos avances llevados a la práctica clínica podrían reducir el impacto de esta patología en la salud materna.

Introduction: preeclampsia is an important cause of maternal and perinatal morbi-mortality throughout the world. Its etiopathogeny still remains an enigma; however, the advances made in genomics and proteomics promise early identification of the disease or the risk of suffering from it. Objective: thoughts on the most promising advances in genomics and proteomics regarding the pressing goal of early detection and/or prediction of preeclampsia risk. Conclusions: two functional polymorphisms, one on the ACE gene (I/D) and another one in the COMT gene (Val158Met) are the most promising results of genomics for identifying women at genetically higher risk of developing preeclampsia during pregnancy. Proteomics has identified SERPINA-1 as a useful biomarker for detecting preeclampsia in the urine of pregnant women at least 10 weeks before clinical manifestations as well as the need for early termination of pregnancy. Such recent progress in genomics and proteomics adapted to clinical practice might reduce the impact of this disease on maternal health.

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