RESUMO
OBJECTIVE: We aimed to broaden our understanding of a potential interaction between B1R and TLR4, considering earlier studies suggesting that lipopolysaccharide (LPS) may trigger B1R stimulation. METHODS: We assessed the impact of DBK and LPS on the membrane potential of thoracic aortas from C57BL/6, B1R, or TLR4 knockout mice. Additionally, we examined the staining patterns of these receptors in the thoracic aortas of C57BL/6 and in endothelial cells (HBMEC). RESULTS: DBK does not affect the resting membrane potential of aortic rings in C57BL/6 mice, but it hyperpolarizes preparations in B1KO and TLR4KO mice. The hyperpolarization mechanism in B1KO mice involves B2R, and the TLR4KO response is independent of cytoplasmic calcium influx but relies on potassium channels. Conversely, LPS hyperpolarizes thoracic aorta rings in both C57BL/6 and B1KO mice, with the response unaffected by a B1R antagonist. Interestingly, the absence of B1R alters the LPS response to potassium channels. These activities are independent of nitric oxide synthase (NOS). While exposure to DBK and LPS does not alter B1R and TLR4 mRNA expression, treatment with these agonists increases B1R staining in endothelial cells of thoracic aortic rings and modifies the staining pattern of B1R and TLR4 in endothelial cells. Proximity ligation assay suggests a interaction between the receptors. CONCLUSION: Our findings provide additional support for a putative connection between B1R and TLR4 signaling. Given the involvement of these receptors and their agonists in inflammation, it suggests that drugs and therapies targeting their effects could be promising therapeutic avenues worth exploring.
Assuntos
Aorta Torácica , Células Endoteliais , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor B1 da Bradicinina , Receptor 4 Toll-Like , Animais , Masculino , Camundongos , Aorta Torácica/metabolismo , Bradicinina/farmacologia , Bradicinina/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Receptor B1 da Bradicinina/metabolismo , Receptor B1 da Bradicinina/genética , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , FemininoRESUMO
Bradykinin (BK), a well-studied mediator of physiological and pathological processes in the peripheral system, has garnered less attention regarding its function in the central nervous system, particularly in behavioural regulation. This review delves into the historical progression of research focused on the behavioural effects of BK and other drugs that act via similar mechanisms to provide new insights into the pathophysiology and pharmacotherapy of psychiatric disorders. Evidence from experiments with animal models indicates that BK modulates defensive reactions associated with panic symptoms and the response to acute stressors. The mechanisms are not entirely understood but point to complex interactions with other neurotransmitter systems, such as opioids, and intracellular signalling cascades. By addressing the existing research gaps in this field, we present new proposals for future research endeavours to foster a new era of investigation regarding BK's role in emotional regulation. Implications for psychiatry, chiefly for panic and depressive disorders are also discussed.
Assuntos
Bradicinina , Sistema Nervoso Central , Humanos , Animais , Bradicinina/metabolismo , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/efeitos dos fármacos , Transtorno de Pânico/metabolismo , Transtornos Mentais/metabolismo , Transtornos Mentais/tratamento farmacológico , Transtorno Depressivo/metabolismo , Transtorno Depressivo/tratamento farmacológicoRESUMO
Cerebral malaria (CM) pathogenesis is described as a multistep mechanism. In this context, monocytes have been implicated in CM pathogenesis by increasing the sequestration of infected red blood cells to the brain microvasculature. In disease, endothelial activation is followed by reduced monocyte rolling and increased adhesion. Nowadays, an important challenge is to identify potential pro-inflammatory stimuli that can modulate monocytes behavior. Our group have demonstrated that bradykinin (BK), a pro-inflammatory peptide involved in CM, is generated during the erythrocytic cycle of P. falciparum and is detected in culture supernatant (conditioned medium). Herein we investigated the role of BK in the adhesion of monocytes to endothelial cells of blood brain barrier (BBB). To address this issue human monocytic cell line (THP-1) and human brain microvascular endothelial cells (hBMECs) were used. It was observed that 20% conditioned medium from P. falciparum infected erythrocytes (Pf-iRBC sup) increased the adhesion of THP-1 cells to hBMECs. This effect was mediated by BK through the activation of B2 and B1 receptors and involves the increase in ICAM-1 expression in THP-1 cells. Additionally, it was observed that angiotensin-converting enzyme (ACE) inhibitor, captopril, enhanced the effect of both BK and Pf-iRBC sup on THP-1 adhesion. Together these data show that BK, generated during the erythrocytic cycle of P. falciparum, could play an important role in adhesion of monocytes in endothelial cells lining the BBB.
Assuntos
Barreira Hematoencefálica , Bradicinina , Adesão Celular , Malária Cerebral , Malária Falciparum , Plasmodium falciparum , Humanos , Bradicinina/metabolismo , Adesão Celular/fisiologia , Meios de Cultivo Condicionados/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Eritrócitos/parasitologia , Malária Cerebral/metabolismo , Malária Cerebral/parasitologia , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Monócitos/fisiologia , Plasmodium falciparum/fisiologia , Barreira Hematoencefálica/fisiopatologiaRESUMO
Spatial confinement and temporal regulation of signaling by nitric oxide (NO) and reactive oxygen species (ROS) occurs in cancer cells. Signaling mediated by NO and ROS was investigated in two sub clones of the murine melanoma B16F10-Nex2 cell line, Nex10C and Nex8H treated or not with bradykinin (BK). The sub clone Nex10C, similar to primary site cells, has a low capacity for colonizing the lungs, whereas the sub clone Nex8H, similar to metastatic cells, corresponds to a highly invasive melanoma. BK-treated Nex10C cells exhibited a transient increase in NO and an inhibition in basal O2- levels. Inhibition of endogenous NO production by l-NAME resulted in detectable levels of O2-. l-NAME promoted Rac1 activation and enhanced Rac1-PI3K association. l-NAME in the absence of BK resulted in Nex10C cell migration and invasion, suggesting that NO is a negative regulator of O2- mediated cell migration and cell invasion. BK-treated Nex8H cells sustained endogenous NO production through the activation of NOS3. NO activated Rac1 and promoted Rac1-PI3K association. NO stimulated cell migration and cell invasion through a signaling axis involving Ras, Rac1 and PI3K. In conclusion, a role for O2- and NO as positive regulators of Rac1-PI3K signaling associated with cell migration and cell invasion is proposed respectively for Nex10C and Nex8H murine melanoma cells.
Assuntos
Bradicinina , Melanoma , Camundongos , Animais , Bradicinina/farmacologia , Bradicinina/metabolismo , Superóxidos , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Movimento CelularRESUMO
Angioedema is a prevailing symptom in different diseases, frequently occurring in the presence of urticaria. Recurrent angioedema without urticaria (AE) can be hereditary (HAE) and acquired (AAE), and several subtypes can be distinguished, although clinical presentation is quite similar in some of them. They present with subcutaneous and mucosal swellings, affecting extremities, face, genitals, bowels, and upper airways. AE is commonly misdiagnosed due to restricted access and availability of appropriate laboratorial tests. HAE with C1 inhibitor defect is associated with quantitative and/or functional deficiency. Although bradykinin-mediated disease results mainly from disturbance in the kallikrein-kinin system, traditionally complement evaluation has been used for diagnosis. Diagnosis is established by nephelometry, turbidimetry, or radial immunodiffusion for quantitative measurement of C1 inhibitor, and chromogenic assay or ELISA has been used for functional C1-INH analysis. Wrong handling of the samples can lead to misdiagnosis and, consequently, mistaken inappropriate approaches. Dried blood spot (DBS) tests have been used for decades in newborn screening for certain metabolic diseases, and there has been growing interest in their use for other congenital conditions. Recently, DBS is now proposed as an efficient tool to diagnose HAE with C1 inhibitor deficiency, and its use would improve the access to outbound areas and family members. Regarding HAE with normal C1 inhibitor, complement assays' results are normal and the genetic sequencing of target genes, such as exon 9 of F12 and PLG, is the only available method. New methods to measure cleaved high-molecular-weight kininogen and activated plasma kallikrein have emerged as potential biochemical tests to identify bradykinin-mediated angioedema. Validated biomarkers of kallikrein-kinin system activation could be helpful in differentiating mechanisms of angioedema. Our aim is to focus on the capability to differentiate histaminergic AE from bradykinin-mediated AE. In addition, we will describe the challenges developing specific tests like direct bradykinin measurements. The need for quality tests to improve the diagnosis is well represented by the variability of results in functional assays.
Assuntos
Angioedema/diagnóstico , Angioedemas Hereditários/diagnóstico , Erros de Diagnóstico/prevenção & controle , Angioedema/sangue , Angioedema/imunologia , Angioedemas Hereditários/sangue , Angioedemas Hereditários/genética , Angioedemas Hereditários/imunologia , Biomarcadores/sangue , Biomarcadores/metabolismo , Bradicinina/sangue , Bradicinina/imunologia , Bradicinina/metabolismo , Proteína Inibidora do Complemento C1/análise , Proteína Inibidora do Complemento C1/genética , Proteína Inibidora do Complemento C1/metabolismo , Análise Mutacional de DNA , Diagnóstico Diferencial , Teste em Amostras de Sangue Seco/métodos , Ensaio de Imunoadsorção Enzimática , Fator XII/genética , Humanos , Mutação , Plasminogênio/genética , RecidivaRESUMO
The global SARS-CoV-2 pandemic starting in 2019 has already reached more than 2.3 million deaths. Despite the scientific community's efforts to investigate the COVID-19 disease, a drug for effectively treating or curing patients yet needs to be discovered. Hematopoietic stem cells (HSC) differentiating into immune cells for defense express COVID-19 entry receptors, and COVID-19 infection hinders their differentiation. The importance of purinergic signaling in HSC differentiation and innate immunity has been recognized. The metabotropic P2Y14 receptor subtype, activated by UDP-glucose, controls HSC differentiation and mobilization. Thereon, the exacerbated activation of blood immune cells amplifies the inflammatory state observed in COVID-19 patients, specially through the continuous release of reactive oxygen species and extracellular neutrophil traps (NETs). Further, the P2Y14 subtype, robustly inhibits the infiltration of neutrophils into various epithelial tissues, including lungs and kidneys. Here we discuss findings suggesting that antagonism of the P2Y14 receptor could prevent the progression of COVID-19-induced systemic inflammation, which often leads to severe illness and death cases. Considering the modulation of neutrophil recruitment of extreme relevance for respiratory distress and lung failure prevention, we propose that P2Y14 receptor inhibition by its selective antagonist PPTN could limit neutrophil recruitment and NETosis, hence limiting excessive formation of oxygen reactive species and proteolytic activation of the kallikrein-kinin system and subsequent bradykinin storm in the alveolar septa of COVID-19 patients.
Assuntos
COVID-19/terapia , Transplante de Células-Tronco Hematopoéticas , Inflamação/terapia , Receptores Purinérgicos P2/genética , Síndrome do Desconforto Respiratório/terapia , Bradicinina/metabolismo , COVID-19/complicações , COVID-19/patologia , COVID-19/virologia , Quimiotaxia/efeitos dos fármacos , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/virologia , Humanos , Inflamação/patologia , Inflamação/virologia , Pulmão/patologia , Pulmão/virologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Neutrófilos/virologia , Pandemias , Receptores Purinérgicos P2/efeitos dos fármacos , Síndrome do Desconforto Respiratório/complicações , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/virologia , SARS-CoV-2/patogenicidadeRESUMO
BACKGROUND: SARS-CoV-2, the virus that causes COVID-19, enters the cells through a mechanism dependent on its binding to angiotensin-converting enzyme 2 (ACE2), a protein highly expressed in the lungs. The putative viral-induced inhibition of ACE2 could result in the defective degradation of bradykinin, a potent inflammatory substance. We hypothesize that increased bradykinin in the lungs is an important mechanism driving the development of pneumonia and respiratory failure in COVID-19. METHODS: This is a phase II, single-center, three-armed parallel-group, open-label, active control superiority randomized clinical trial. One hundred eighty eligible patients will be randomly assigned in a 1:1:1 ratio to receive either the inhibitor of C1e/kallikrein 20 U/kg intravenously on day 1 and day 4 plus standard care; or icatibant 30 mg subcutaneously, three doses/day for 4 days plus standard care; or standard care alone, as recommended in the clinical trials published to date, which includes supplemental oxygen, non-invasive and invasive ventilation, antibiotic agents, anti-inflammatory agents, prophylactic antithrombotic therapy, vasopressor support, and renal replacement therapy. DISCUSSION: Accumulation of bradykinin in the lungs is a common side effect of ACE inhibitors leading to cough. In animal models, the inactivation of ACE2 leads to severe acute pneumonitis in response to lipopolysaccharide (LPS), and the inhibition of bradykinin almost completely restores the lung structure. We believe that inhibition of bradykinin in severe COVID-19 patients could reduce the lung inflammatory response, impacting positively on the severity of disease and mortality rates. TRIAL REGISTRATION: Brazilian Clinical Trials Registry Universal Trial Number (UTN) U1111-1250-1843. Registered on May/5/2020.
Assuntos
Bradicinina/análogos & derivados , Tratamento Farmacológico da COVID-19 , Proteína Inibidora do Complemento C1/administração & dosagem , Insuficiência Respiratória/tratamento farmacológico , Adulto , Enzima de Conversão de Angiotensina 2/metabolismo , Bradicinina/administração & dosagem , Bradicinina/efeitos adversos , Bradicinina/antagonistas & inibidores , Bradicinina/imunologia , Bradicinina/metabolismo , Antagonistas de Receptor B2 da Bradicinina/administração & dosagem , Antagonistas de Receptor B2 da Bradicinina/efeitos adversos , Brasil , COVID-19/complicações , COVID-19/imunologia , COVID-19/virologia , Ensaios Clínicos Fase II como Assunto , Proteína Inibidora do Complemento C1/efeitos adversos , Esquema de Medicação , Quimioterapia Combinada/efeitos adversos , Quimioterapia Combinada/métodos , Humanos , Injeções Intravenosas , Injeções Subcutâneas , Calicreínas/antagonistas & inibidores , Calicreínas/metabolismo , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Respiratória/imunologia , Insuficiência Respiratória/virologia , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/patogenicidade , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
INTRODUCTION: The pleiotropic kininogen-kallikrein-kinin system is upregulated in pregnancy and localizes in the uteroplacental unit. To identify the systemic and local participation of the bradykinin type 2 receptor (B2R), this was antagonized by Bradyzide (BDZ) during 2 periods: from days 20 to 34 and from days 20 to 60 in pregnant guinea pigs. METHODS: Pregnant guinea pigs received subcutaneous infusions of saline or BDZ from gestational day 20 until sacrifice on day 34 (Short B2R Antagonism [SH-B2RA]) or on day 60 (Prolonged B2R Antagonism [PR-B2RA]). In SH-BDZA, systolic blood pressure was determined on day 34, while in PR-BDZA it was measured preconceptionally, at days 40 and 60. On gestational day 60, plasma creatinine, uricemia, proteinuria, fetal, placental and maternal kidney weight, and the extent of trophoblast invasion were evaluated. RESULTS: The SH-B2RA increased systolic blood pressure on day 34 and reduced trophoblast myometrial invasion, spiral artery remodeling, and placental sufficiency. The PR-B2RA suppressed the normal blood pressure fall observed on days 40 and 60; vascular transformation, placental efficiency, urinary protein, serum creatinine, and uric acid did not differ between the groups. The proportion of all studied mothers with lost fetuses was greater under BDZ infusion than in controls. CONCLUSION: The increased systolic blood pressure and transient reduction in trophoblast invasion and fetal/placental weight in the SH-B2R blockade and the isolated impact on blood pressure in the PR-B2R blockade indicate that bradykinin independently modulates systemic hemodynamics and the uteroplacental unit through cognate vascular and local B2R receptors.
Assuntos
Pressão Sanguínea/fisiologia , Antagonistas dos Receptores da Bradicinina/farmacologia , Bradicinina/metabolismo , Receptor B2 da Bradicinina/metabolismo , Trofoblastos/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicinina/antagonistas & inibidores , Feminino , Cobaias , Placenta/efeitos dos fármacos , Placenta/metabolismo , Gravidez , Pirrolidinas/farmacologia , Tiossemicarbazonas/farmacologia , Trofoblastos/efeitos dos fármacosRESUMO
Chagas cardiomyopathy is the most severe manifestation of human Chagas disease and represents the major cause of morbidity and mortality in Latin America. We previously demonstrated diastolic Ca2+ alterations in cardiomyocytes isolated from Chagas' patients to different degrees of cardiac dysfunction. In addition, we have found a significant elevation of diastolic [Na+]d in Chagas' cardiomyocytes (FCII>FCI) that was greater than control. Exposure of cardiomyocytes to agents that enhance inositol 1,4,5 trisphosphate (IP3) generation or concentration like endothelin (ET-1) or bradykinin (BK), or membrane-permeant myoinositol 1,4,5-trisphosphate hexakis(butyryloxy-methyl) esters (IP3BM) caused an elevation in diastolic [Ca2+] ([Ca2+]d) that was always greater in cardiomyocytes from Chagas' than non- Chagas' subjects, and the magnitude of the [Ca2+]d elevation in Chagas' cardiomyocytes was related to the degree of cardiac dysfunction. Incubation with xestospongin-C (Xest-C), a membrane-permeable selective blocker of the IP3 receptors (IP3Rs), significantly reduced [Ca2+]d in Chagas' cardiomyocytes but did not have a significant effect on non-Chagas' cells. The effects of ET-1, BK, and IP3BM on [Ca2+]d were not modified by the removal of extracellular [Ca2+]e. Furthermore, cardiomyocytes from Chagas' patients had a significant decrease in the sarcoplasmic reticulum (SR) Ca2+content compared to control (Control>FCI>FCII), a higher intracellular IP3 concentration ([IP3]i) and markedly depressed contractile properties compared to control cardiomyocytes. These results provide additional and convincing support about the implications of IP3 in the pathogenesis of Chagas cardiomyopathy in patients at different stages of chronic infection. Additionally, these findings open the door for novel therapeutic strategies oriented to improve cardiac function and quality of life of individuals suffering from chronic Chagas cardiomyopathy (CC).
Assuntos
Cálcio/metabolismo , Cardiomiopatia Chagásica/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Miócitos Cardíacos/metabolismo , Adulto , Bradicinina/metabolismo , Permeabilidade da Membrana Celular , Endotelinas/metabolismo , Feminino , Humanos , Compostos Macrocíclicos/metabolismo , Masculino , Pessoa de Meia-Idade , Oxazóis/metabolismo , Qualidade de Vida , Retículo Sarcoplasmático/metabolismo , Sódio/metabolismoRESUMO
Fibromyalgia is a disease characterised as generalised chronic primary pain that causes functional disability and a reduction in patients' quality of life, without specific pathophysiology or appropriate treatment. Previous studies have shown that kinins and their B1 and B2 receptors contribute to chronic painful conditions. Thus, we investigated the involvement of kinins and their B1 and B2 receptors in a fibromyalgia-like pain model induced by reserpine in mice. Nociceptive parameters (mechanical allodynia, cold sensitivity and overt nociception) and behaviours of burrowing, thigmotaxis, and forced swimming were evaluated after reserpine administration in mice. The role of kinin B1 and B2 receptors was investigated using knockout mice or pharmacological antagonism. The protein expression of kinin B1 and B2 receptors and the levels of bradykinin and monoamines were measured in the sciatic nerve, spinal cord and cerebral cortex of the animals. Knockout mice for the kinin B1 and B2 receptor reduced reserpine-induced mechanical allodynia. Antagonism of B1 and B2 receptors also reduced mechanical allodynia, cold sensitivity and overt nociception reserpine-induced. Reserpine altered thigmotaxis, forced swimming and burrowing behaviour in the animals; with the latter being reversed by antagonism of kinin B1 receptor. Moreover, reserpine increased the protein expression of kinin B1 and B2 receptors and levels of kinin, as well as reduced the levels of monoamines in peripheral and central structures. Kinins and its B1 and B2 receptors are involved in fibromyalgia-like pain symptoms. B1 or B2 receptors might represent a potential target for the relief of fibromyalgia-like pain symptoms.