RESUMEN
The kallikrein-kinin system has been implicated in body weight and glucose homeostasis. Their major effectors act by binding to the kinin B2 and B1 receptors. It was assessed the role of the kinin B1 receptor in weight and glucose homeostasis in B1 receptor knockout mice (B1RKO) subjected to a cafeteria diet (CAF). Wild-type (WT) and B1RKO male mice (C57BL/6 background; 8 weeks old) were fed a standard diet (SD) or CAF for 14 weeks, ad libitum, and four groups were formed: WT-SD; B1RKO-SD; WT-CAF; B1RKO-CAF. Body weight and food intake were assessed weekly. It was performed glucose tolerance (GTT) and insulin tolerance tests (ITT), and HOMA-IR, HOMA-ß and HOMA-ß* 1/HOMA-IR were calculated. Islets from WT and B1RKO were isolated in order to measure the insulin secretion. Western blot was used to assess the hepatic AKT phosphorylation and qPCR to assess gene expression. CAF induced a higher body mass gain in B1RKO compared to WT mice. CAF diet increased epididymal fat depot mass, hepatic fat infiltration and hepatic AKT phosphorylation in both genotypes. However, B1RKO mice presented lower glycemic response during GTT when fed with CAF, and a lower glucose decrease in the ITT. This higher resistance was overcomed with higher insulin secretion when stimulated by high glucose, resulting in higher glucose uptake in the GTT when submitted to CAF, despite lower insulin sensitivity. Islets from B1RKO delivered 4 times more insulin in 3-month-old mice than islets from WT. The higher insulin disposition index and high insulin delivery of B1RKO can explain the decreased glucose excursion during GTT. In conclusion, CAF increased the ß-cell function in B1RKO mice, compensated by the diet-induced insulin resistance and resulting in a healthier glycemic response despite the higher weight gain.
Asunto(s)
Hiperinsulinismo , Resistencia a la Insulina , Receptores de Bradiquinina/metabolismo , Animales , Glucemia/metabolismo , Dieta , Dieta Alta en Grasa , Glucosa/metabolismo , Homeostasis , Insulina/metabolismo , Resistencia a la Insulina/fisiología , Cininas , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Proto-Oncogénicas c-akt , Aumento de PesoRESUMEN
INTRODUCTION: Obesity-related metabolic diseases occur as a result of disruptions in white adipose tissue (WAT) plasticity, especially through visceral fat accumulation and adipocyte hypertrophy. This study aimed to evaluate the impact of renin-angiotensin system (RAS) and bradykinin receptors modulation by enalapril treatment and/or exercise training on WAT morphology and related deleterious outcomes. METHODS: Male C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At the 8th week, HF-fed animals were divided into sedentary (HF), enalapril treatment (HF-E), exercise training (HF-T), and enalapril treatment plus exercise training (HF-ET) groups. Following the experimental protocol, body mass gain, adiposity index, insulin resistance, visceral WAT morphometry, renin-angiotensin system, and bradykinin receptors were evaluated. RESULTS: The HF group displayed increased adiposity, larger visceral fat mass, and adipocyte hypertrophy, which was accompanied by insulin resistance, overactivation of Ang II/AT1R arm, and favoring of B1R in bradykinin receptors profile. All interventions ameliorated visceral adiposity and related outcomes by favoring the Ang 1-7/MasR arm and the B2R expression in B1R/B2R ratio. However, combined therapy additively reduced Ang II/Ang 1-7 ratio. CONCLUSION: Our results suggest that Ang 1-7/MasR arm and B2R activation might be relevant targets in the treatment of visceral obesity.
Asunto(s)
Enalapril/farmacología , Condicionamiento Físico Animal/fisiología , Sistema Renina-Angiotensina/fisiología , Tejido Adiposo Blanco/metabolismo , Adiposidad/efectos de los fármacos , Adiposidad/fisiología , Animales , Dieta Alta en Grasa , Enalapril/metabolismo , Insulina/metabolismo , Resistencia a la Insulina/fisiología , Grasa Intraabdominal/efectos de los fármacos , Grasa Intraabdominal/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Obesidad Abdominal/metabolismo , Receptores de Bradiquinina/metabolismo , Sistema Renina-Angiotensina/efectos de los fármacosRESUMEN
Intermittent hypoxia (IH) is a feature of obstructive sleep apnea (OSA), a condition highly associated with hypertension-related cardiovascular diseases. Repeated episodes of IH contribute to imbalance of angiogenic growth factors in the hypertrophic heart, which is key in the progression of cardiovascular complications. In particular, the interaction between vascular endothelial growth factor (VEGF) and the kallikrein-kinin system (KKS) is essential for promoting angiogenesis. However, researchers have yet to investigate experimental models of IH that reproduce OSA, myocardial angiogenesis, and expression of KKS components. We examined temporal changes in cardiac angiogenesis in a mouse IH model. Adult male C57BI/6 J mice were implanted with Matrigel plugs and subjected to IH for 1-5 weeks with subsequent weekly histological evaluation of vascularization. Expression of VEGF and KKS components was also evaluated. After 3 weeks, in vivo myocardial angiogenesis and capillary density were decreased, accompanied by a late increase of VEGF and its type 2 receptor. Furthermore, IH increased left ventricular myocardium expression of the B2 bradykinin receptor, while reducing mRNA levels of B1 receptor. These results suggest that in IH, an unexpected response of the VEGF and KKS systems could explain the reduced capillary density and impaired angiogenesis in the hypoxic heart, with potential implications in hypertrophic heart malfunction.
Asunto(s)
Cardiomegalia/metabolismo , Hipoxia/metabolismo , Cininas/metabolismo , Miocardio/metabolismo , Neovascularización Fisiológica , Apnea Obstructiva del Sueño/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Capilares/metabolismo , Capilares/fisiología , Cardiomegalia/complicaciones , Vasos Coronarios/metabolismo , Vasos Coronarios/fisiología , Hipoxia/complicaciones , Calicreínas/genética , Calicreínas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Receptores de Bradiquinina/genética , Receptores de Bradiquinina/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular/genética , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Apnea Obstructiva del Sueño/complicaciones , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
Fibromyalgia is a potentially disabling chronic disease, characterized by widespread pain and a range of comorbidities such as hypertension. Among the mechanisms involved in fibromyalgia-like pain symptoms are kinins and their B1 and B2 receptors. Moreover, angiotensin I converting enzyme (ACE) inhibitors, commonly used as antihypertensive drugs, can enhance pain by blocking the degradation of peptides such as substance P and bradykinin, besides enhancing kinin receptors signalling. We investigated the effect of ACE inhibitors on reserpine-induced fibromyalgia-like pain symptoms and the involvement of kinins in this effect in mice. Nociceptive parameters (mechanical and cold allodynia and overt nociception) were evaluated after ACE inhibitors administration in mice previously treated with reserpine. The role of kinin B1 and B2 receptors was investigated using pharmacological antagonism. Additionally, bradykinin levels, as well as the activity of ACE and kininase I, were measured in the sciatic nerve, spinal cord and cerebral cortex of the mice. The ACE inhibitors enalapril and captopril enhanced reserpine-induced mechanical allodynia, and this increase was prevented by kinin B1 and B2 receptor antagonists. Substance P and bradykinin caused overt nociception and increased mechanical allodynia in animals treated with reserpine. Reserpine plus ACE inhibitors increased bradykinin-related peptide levels and inhibited ACE activity in pain modulation structures. Since hypertension is a frequent comorbidity affecting fibromyalgia patients, hypertension treatment with ACE inhibitors in these patients should be reviewed once this could enhance fibromyalgia-like pain symptoms. Thus, the treatment of hypertensive patients with fibromyalgia could include other classes of antihypertensive drugs, different from ACE inhibitors.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/toxicidad , Fibromialgia/inducido químicamente , Sistema Nervioso/efectos de los fármacos , Dolor Nociceptivo/inducido químicamente , Umbral del Dolor/efectos de los fármacos , Peptidil-Dipeptidasa A/metabolismo , Receptores de Bradiquinina/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Captopril/toxicidad , Modelos Animales de Enfermedad , Enalapril/toxicidad , Fibromialgia/enzimología , Fibromialgia/fisiopatología , Masculino , Ratones , Sistema Nervioso/enzimología , Sistema Nervioso/fisiopatología , Dolor Nociceptivo/enzimología , Dolor Nociceptivo/fisiopatología , Reserpina , Transducción de SeñalRESUMEN
Complex regional pain syndrome type-I (CRPS-I) is a chronic painful condition resulting from trauma. Bradykinin (BK) is an important inflammatory mediator required in acute and chronic pain response. The objective of this study was to evaluate the association between BK receptors (B1 and B2) and chronic post-ischaemia pain (CPIP) development in mice, a widely accepted CRPS-I model. We assessed mechanical and cold allodynia, and paw oedema in male and female Swiss mice exposed to the CPIP model. Upon induction, the animals were treated with BKR antagonists (HOE-140 and DALBK); BKR agonists (Tyr-BK and DABK); antisense oligonucleotides targeting B1 and B2 and captopril by different routes in the model (7, 14 and 21 days post-induction). Here, we demonstrated that treatment with BKR antagonists, by intraperitoneal (i.p.), intraplantar (i.pl.), and intrathecal (i.t.) routes, mitigated CPIP-induced mechanical allodynia and oedematogenic response, but not cold allodynia. On the other hand, i.pl. administration of BKR agonists exacerbated pain response. Moreover, a single treatment with captopril significantly reversed the anti-allodynic effect of BKR antagonists. In turn, the inhibition of BKRs gene expression in the spinal cord inhibited the nociceptive behaviour in the 14th post-induction. The results of the present study suggest the participation of BKRs in the development and maintenance of chronic pain associated with the CPIP model, possibly linking them to CRPS-I pathogenesis.
Asunto(s)
Dolor Crónico/etiología , Dolor Crónico/metabolismo , Isquemia/complicaciones , Receptores de Bradiquinina/metabolismo , Animales , Antagonistas de los Receptores de Bradiquinina/farmacología , Inhibidores de la Colinesterasa/farmacología , Dolor Crónico/genética , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Silenciador del Gen/efectos de los fármacos , Hiperalgesia/complicaciones , Masculino , Ratones , Nocicepción/efectos de los fármacos , Receptores de Bradiquinina/genética , Médula Espinal/patologíaRESUMEN
The regulation of the kallikrein-kinin system is an important mechanism controlling vasodilation and promoting inflammation. We aimed to investigate the role of Toll-like receptor 2 (TLR2) in regulating kinin B1 and B2 receptor expression in human gingival fibroblasts and in mouse gingiva. Both P. gingivalis LPS and the synthetic TLR2 agonist Pam2CSK4 increased kinin receptor transcripts. Silencing of TLR2, but not of TLR4, inhibited the induction of kinin receptor transcripts by both P. gingivalis LPS and Pam2CSK4. Human gingival fibroblasts (HGF) exposed to Pam2CSK4 increased binding sites for bradykinin (BK, B2 receptor agonist) and des-Arg10-Lys-bradykinin (DALBK, B1 receptor agonist). Pre-treatment of HGF for 24 h with Pam2CSK4 resulted in increased PGE2 release in response to BK and DALBK. The increase of B1 and B2 receptor transcripts by P. gingivalis LPS was not blocked by IL-1ß neutralizing antibody; TNF-α blocking antibody did not affect B1 receptor up-regulation, but partially blocked increase of B2 receptor mRNA. Injection of P. gingivalis LPS in mouse gingiva induced an increase of B1 and B2 receptor mRNA. These data show that activation of TLR2 in human gingival fibroblasts as well as in mouse gingival tissue leads to increase of B1 and B2 receptor mRNA and protein.
Asunto(s)
Receptores de Bradiquinina/genética , Receptor Toll-Like 2/metabolismo , Adulto , Animales , Bradiquinina/metabolismo , Femenino , Fibroblastos/metabolismo , Encía/metabolismo , Humanos , Inflamación/metabolismo , Cininas/metabolismo , Lipopéptidos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Receptor de Bradiquinina B1/genética , Receptor de Bradiquinina B2/genética , Receptores de Bradiquinina/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
OBJECTIVE: We investigated whether: (1) P2 × 7 receptor activation by its agonist (BzATP) induces articular hyperalgesia in the rat's knee joint via inflammatory mechanisms and (2) activation of P2 × 7 receptors by endogenous ATP contributes to the articular hyperalgesia induced by bradykinin, TNF-α, IL-1ß, CINC-1, PGE2, and dopamine. METHODS: The articular hyperalgesia was quantified using the rat knee joint incapacitation test. The knee joint inflammation, characterized by the concentration of pro-inflammatory cytokines and by neutrophil migration, was quantified in the synovial lavage fluid by ELISA and myeloperoxidase enzyme activity assay, respectively. RESULTS: BzATP induced a dose-dependent articular hyperalgesia in the rat's knee joint that was significantly reduced by the selective antagonists for P2 × 7, bradykinin B1 or B2 receptors, ß1 or ß2 adrenoceptors, and by pre-treatment with Indomethacin. BzATP induced a local increase of TNF-α, IL-1ß, IL-6, and CINC-1 concentration and neutrophil migration into the knee joint. The co-administration of the selective P2 × 7 receptor antagonist A-740003 significantly reduced the articular hyperalgesia induced by bradykinin and dopamine, but not by TNF-α, IL-1ß, CINC-1, and PGE2. CONCLUSIONS: P2 × 7 receptor activation induces articular hyperalgesia mediated by the previous inflammatory mediator release. P2 × 7 receptor-induced articular hyperalgesia is sustained by the involvement of this purinergic receptor in bradykinin and dopamine-induced hyperalgesia in the knee joint.
Asunto(s)
Hiperalgesia/etiología , Articulación de la Rodilla/metabolismo , Receptores de Bradiquinina/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Adenosina Trifosfato/análogos & derivados , Antagonistas Adrenérgicos beta/farmacología , Animales , Bradiquinina , Antagonistas de los Receptores de Bradiquinina/farmacología , Citocinas/metabolismo , Dopamina , Hiperalgesia/inducido químicamente , Hiperalgesia/metabolismo , Mediadores de Inflamación/metabolismo , Masculino , Antagonistas de Prostaglandina/farmacología , Antagonistas del Receptor Purinérgico P2/farmacología , Agonistas del Receptor Purinérgico P2X/farmacología , Antagonistas del Receptor Purinérgico P2X/farmacología , Ratas WistarRESUMEN
Hereditary angioedema (HAE) with C1 inhibitor deficiency is a genetic disorder that clinically manifests with attacks of angioedema in the subcutaneous and submucosal tissues, mainly in the extremities, abdomen, and upper airway. During attacks, vascular permeability is increased due to increased bradykinin (BK). This means that special therapies are needed for attacks that do not respond to traditional antiallergic therapies involving antihistamines, corticosteroids, and epinephrine. The recurring attacks may disable patients and lead to frequent visits to emergency rooms where misdiagnoses are common. HAE attacks may be fatal when upper-airway edema occurs, if proper treatment with a C1 inhibitor concentrate or BK receptor antagonist is not administered or an emergency tracheostomy is not performed. We propose a mnemonic method for the warning signs of HAE for the use as a diagnostic tool, i.e., the so-called "ABC" of the warning signs of HAE. The letters represent the following: A = Angioedema, B = Bradykinin, C = C1 inhibitor, D = Distress factors, E = Epinephrine nonresponsive, F = Family history, and G = Glottis/Gastrointestinal edema. To avoid fatalities, medical staff and patients, including family members, must be aware of HAE. An alphabetical mnemonic method has been developed and we hope it may benefit patients.
Asunto(s)
Angioedemas Hereditarios/diagnóstico , Angioedemas Hereditarios/tratamiento farmacológico , Antagonistas de los Receptores de Bradiquinina/uso terapéutico , Bradiquinina/análogos & derivados , Proteínas Inactivadoras del Complemento 1/deficiencia , Angioedemas Hereditarios/patología , Bradiquinina/metabolismo , Bradiquinina/uso terapéutico , Permeabilidad Capilar/genética , Permeabilidad Capilar/fisiología , Proteínas Inactivadoras del Complemento 1/genética , Proteína Inhibidora del Complemento C1 , Predisposición Genética a la Enfermedad/genética , Humanos , Receptores de Bradiquinina/metabolismoRESUMEN
The objective of this study was to evaluate the effects of photobiomodulation therapy (PBMT) on inflammatory indicators, i.e., inflammatory mediators (TNF-α and CINC-1), and pain characterized by hyperalgesia and B1 and B2 receptor activation at 6, 24, and 48 h after papain-induced osteoarthritis (OA) in rats. Fifty-four rats were subjected to hyperalgesia evaluations and then divided randomly into three groups-a control group and two groups OA and OA PBMT group by using laser parameters at wavelength (808 nm), output power (50 mW), energy per point (4 Joules), power density (1.78 W/cm2), laser beam (0.028 cm2), and energy density (144 J/cm2)-the induction of osteoarthritis was then performed with 20-µl injections of a 4 % papain solution dissolved in 10 µl of saline solution, to which 10 µl of cysteine solution (0.03 M). The statistical analysis was performed using two-way ANOVA with Bonferroni's post hoc test for comparisons between the 6, 24, and 48 h and team points within each group, and between the control, injury, and PBMT groups, and p < 0.05 was considered to indicate a significant difference. The hyperalgesia was evaluated at 6, 24, and 48 h after the injury. PBMT at a wavelength of 808 nm and doses of 4 J, administered afterward, promotes increase at the threshold of pressure stimulus at 6, 24, and 48 h after application and promote cytokine attenuation levels (TNF and CINC-1) and bradykinin receptor (B1 and B2) along the experimental period. We conclude that photobiomodulation therapy was able to promote the reduction of proinflammatory cytokines such as TNF-α and CINC-1, to reduce the gene and protein expression of the bradykinin receptor (B1 and B2), as well as increasing the stimulus response threshold of pressure in an experimental model of acute osteoarthritis.
Asunto(s)
Mediadores de Inflamación/metabolismo , Terapia por Luz de Baja Intensidad , Osteoartritis/metabolismo , Osteoartritis/radioterapia , Receptores de Bradiquinina/metabolismo , Enfermedad Aguda , Animales , Quimiocina CXCL1 , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Extremidades/patología , Regulación de la Expresión Génica , Hiperalgesia/complicaciones , Hiperalgesia/genética , Hiperalgesia/metabolismo , Hiperalgesia/patología , Masculino , Osteoartritis/complicaciones , Osteoartritis/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Paclitaxel is a chemotherapeutic agent used to treat solid tumours. However, it causes an acute and neuropathic pain syndrome that limits its use. Among the mechanisms involved in neuropathic pain caused by paclitaxel is activation of kinin receptors. Angiotensin converting enzyme (ACE) inhibitors can enhance kinin receptor signalling. The goal of this study was to evaluate the role of kinins on paclitaxel-associated acute pain syndromes (P-APS) and the effect of ACE inhibition on P-APS and paclitaxel-associated chronic peripheral neuropathy (P-CPN) in mice. Herein, we show that paclitaxel caused mechanical allodynia and spontaneous nociceptive behaviour that was reduced by antagonists of kinin receptors B1 (DALBk and SSR240612) and B2 (Hoe140 and FR173657). Moreover, enalapril (an ACE inhibitor) enhanced the mechanical allodynia induced by a low dose of paclitaxel. Likewise, paclitaxel injection inhibited ACE activity and increased the expressions of B1 and B2 receptors and bradykinin-related peptides levels in peripheral tissue. Together, our data support the involvement of kinin receptors in the P-APS and suggest kinin receptor antagonists to treat this syndrome. Because hypertension is the most frequent comorbidity affecting cancer patients, treatment of hypertension with ACE inhibitors in patients undergoing paclitaxel chemotherapy should be reviewed, since this could enhance the P-APS and P-CPN.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/toxicidad , Bradiquinina/metabolismo , Neuralgia/inducido químicamente , Neuralgia/metabolismo , Paclitaxel/toxicidad , Receptores de Bradiquinina/metabolismo , Animales , Antineoplásicos/toxicidad , Sinergismo Farmacológico , Masculino , Ratones , Dimensión del Dolor/efectos de los fármacos , Dimensión del Dolor/métodosRESUMEN
The most aggressive subtype of brain tumors is glioma WHO grade IV, the glioblastoma (GBM). The present work aims to elucidate the role of kinin receptors in interactions between GBM cells and mesenchymal stem cells (MSC). The GBM cell line U87-MG was stably transfected to express dsRed protein, single cell cloned, expanded, and cultured with MSC, both in the direct co-cultures (DC) and indirect co-cultures (IC) at equal cell number ratio for 72 h. Up- and down-regulation of matrix metalloproteases (MMP)-9 expression in U87-MG and MSC cells, respectively, in direct co-culture points to possible MSC participation in tumor invasion. MMP9 expression is in line with significantly increased expression of kinin B1 (B1R) and B2 receptor (B2R) in U87-MG cells and their decreased levels in MSC, as confirmed by quantitative assessment using flow cytometric analysis. Similarly, in indirect cultures (IC), lacking the contact between GBM and MSC cells, an increase of B1 and B2 receptor expression was again noted in U87-MG cells, and no significant changes in kinin receptors in MSC was observed. Functionality of kinin-B1 and B2 receptors was evidenced by stimulation of intracellular calcium fluxes by their respective agonists, des-Arg9-bradykinin (DBK) and bradykinin (BK). Moreover, BK showed a feedback control on kinin receptor expression in mono-cultures, direct and indirect co-cultures. The treatment with BK resulted in down-regulation of B1 and B2 receptors in MSC, with simultaneous up-regulation of these receptors in U87-MG cells, suggesting that functions of BK in information flow between these cells is important for tumor progression and invasion. © 2015 International Society for Advancement of Cytometry.
Asunto(s)
Bradiquinina/metabolismo , Glioblastoma/metabolismo , Células Madre Mesenquimatosas/citología , Receptores de Bradiquinina/metabolismo , Comunicación Celular , Células Cultivadas , Técnicas de Cocultivo , Humanos , Transducción de Señal/fisiología , Regulación hacia ArribaRESUMEN
The kinins bradykinin and des-arg(9) -bradykinin cleaved from kininogen precursors by kallikreins exert their biological actions by stimulating kinin-B2 and B1 receptors, respectively. In vitro models of neural differentiation such as P19 embryonal carcinoma cells and neural progenitor cells have suggested the involvement of B2 receptors in neural differentiation and phenotype determination; however, the involvement of B1 receptors in these processes has not been established. Here, we show that B1 and B2 receptors are differentially expressed in mouse embryonic E14Tg2A stem cells undergoing neural differentiation. Proliferation and differentiation assays, performed in the presence of receptor subtype-selective agonists and antagonists, revealed that B1 receptor activity is required for the proliferation of embryonic and differentiating cells as well as for neuronal maturation at later stages of differentiation, while the B2 receptor acts on neural phenotype choice, promoting neurogenesis over gliogenesis. Besides the elucidation of bradykinin functions in an in vitro model reflecting early embryogenesis and neurogenesis, this study contributes to the understanding of B1 receptor functions in this process.
Asunto(s)
Bradiquinina/metabolismo , Diferenciación Celular/fisiología , Células Madre Embrionarias de Ratones/citología , Células-Madre Neurales/citología , Fenotipo , Receptores de Bradiquinina/metabolismo , Animales , Ratones , Neuronas/citologíaRESUMEN
The kallikrein-kinin system (KKS) is an endogenous pathway involved in many biological processes. Although primarily related to blood pressure control and inflammation, its activation goes beyond these effects. Neurogenesis and neuroprotection might be stimulated by bradykinin being of great interest for clinical applications following brain injury. This peptide is also an important player in spinal cord injury pathophysiology and recovery, in which bradykinin receptor blockers represent substantial therapeutic potential. Here, we highlight the participation of kinin receptors and especially bradykinin in mediating ischemia pathophysiology in the central and peripheral nervous systems. Moreover, we explore the recent advances on mechanistic and therapeutic targets for biological, pathological, and neural repair processes involving kinins.
Asunto(s)
Cininas/metabolismo , Sistema Nervioso/metabolismo , Animales , Humanos , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Neurogénesis , Receptores de Bradiquinina/metabolismo , Traumatismos de la Médula Espinal/fisiopatologíaRESUMEN
Extracellular peptide ligand binding sites, which bind the N-termini of angiotensin II (AngII) and bradykinin (BK) peptides, are located on the N-terminal and extracellular loop 3 regions of the AT(1)R and BKRB(1) or BKRB(2) G-protein-coupled receptors (GPCRs). Here we synthesized peptides P15 and P13 corresponding to these receptor fragments and showed that only constructs in which these peptides were linked by S-S bond, and cyclized by closing the gap between them, could bind agonists. The formation of construct-agonist complexes was revealed by electron paramagnetic resonance spectra and fluorescence measurements of spin labeled biologically active analogs of AngII and BK (Toac(1)-AngII and Toac(0)-BK), where Toac is the amino acid-type paramagnetic and fluorescence quencher 2, 2, 6, 6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid. The inactive derivatives Toac(3)-AngII and Toac(3)-BK were used as controls. The interactions characterized by a significant immobilization of Toac and quenching of fluorescence in complexes between agonists and cyclic constructs were specific for each system of peptide-receptor construct assayed since no crossed reactions or reaction with inactive peptides could be detected. Similarities among AT, BKR, and chemokine receptors were identified, thus resulting in a configuration for AT(1)R and BKRB cyclic constructs based on the structure of the CXCR(4), an α-chemokine GPCR-type receptor.
Asunto(s)
Angiotensina II/agonistas , Bradiquinina/agonistas , Péptidos/química , Receptor de Angiotensina Tipo 1/química , Receptores de Bradiquinina/química , Secuencia de Aminoácidos , Angiotensina II/genética , Angiotensina II/metabolismo , Sitios de Unión , Bradiquinina/genética , Bradiquinina/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Datos de Secuencia Molecular , Péptidos/genética , Péptidos/metabolismo , Unión Proteica , Estructura Secundaria de Proteína , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 1/metabolismo , Receptores de Bradiquinina/genética , Receptores de Bradiquinina/metabolismoRESUMEN
The kallikrein-kinin system (KKS) has been previously linked to glucose homeostasis. In isolated muscle or fat cells, acute bradykinin (BK) stimulation was shown to improve insulin action and increase glucose uptake by promoting glucose transporter 4 translocation to plasma membrane. However, the role for BK in the pathophysiology of obesity and type 2 diabetes remains largely unknown. To address this, we generated genetically obese mice (ob/ob) lacking the BK B2 receptor (obB2KO). Despite similar body weight or fat accumulation, obB2KO mice showed increased fasting glycemia (162.3 ± 28.2 mg/dl vs 85.3 ± 13.3 mg/dl), hyperinsulinemia (7.71 ± 1.75 ng/ml vs 4.09 ± 0.51 ng/ml) and impaired glucose tolerance when compared with ob/ob control mice (obWT), indicating insulin resistance and impaired glucose homeostasis. This was corroborated by increased glucose production in response to a pyruvate challenge. Increased gluconeogenesis was accompanied by increased hepatic mRNA expression of forkhead box protein O1 (FoxO1, four-fold), peroxisome proliferator-activated receptor gamma co-activator 1-alpha (seven-fold), phosphoenolpyruvate carboxykinase (PEPCK, three-fold) and glucose-6-phosphatase (eight-fold). FoxO1 nuclear exclusion was also impaired, as the obB2KO mice showed increased levels of this transcription factor in the nucleus fraction of liver homogenates during random feeding. Intraportal injection of BK in lean mice was able to decrease the hepatic mRNA expression of FoxO1 and PEPCK. In conclusion, BK modulates glucose homeostasis by affecting hepatic glucose production in obWT. These results point to a protective role of the KKS in the pathophysiology of type 2 diabetes mellitus.
Asunto(s)
Bradiquinina/metabolismo , Factores de Transcripción Forkhead/metabolismo , Gluconeogénesis/fisiología , Glucosa/metabolismo , Hígado/metabolismo , Receptores de Bradiquinina/metabolismo , Análisis de Varianza , Animales , Bradiquinina/administración & dosificación , Línea Celular Tumoral , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Modelos Animales de Enfermedad , Femenino , Proteína Forkhead Box O1 , Factores de Transcripción Forkhead/genética , Gluconeogénesis/efectos de los fármacos , Glucosa-6-Fosfatasa/genética , Glucosa-6-Fosfatasa/metabolismo , Humanos , Insulina/metabolismo , Resistencia a la Insulina/genética , Sistema Calicreína-Quinina/fisiología , Leptina/metabolismo , Hígado/enzimología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Obesos , Obesidad/genética , Obesidad/metabolismo , Obesidad/fisiopatología , PPAR gamma/genética , PPAR gamma/metabolismo , Fosfoenolpiruvato Carboxiquinasa (GTP)/genética , Fosfoenolpiruvato Carboxiquinasa (GTP)/metabolismo , Ratas , Receptores de Bradiquinina/genéticaRESUMEN
UNLABELLED: Kinins mediate their cellular effects through B1 (B1R) and B2 (B2R) receptors, and the activation of B2R reduces collagen synthesis in cardiac fibroblasts (CF). However, the question of whether B1R and/or B2R have a role in cardiac myofibroblasts remains unanswered. METHODS: CF were isolated from neonate rats and myofibroblasts were generated by an 84 h treatment with TGF-ß1 (CMF). B1R was evaluated by western blot, immunocytochemistry and radioligand assay; B2R, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and cyclooxygenases 1 and 2 (COX-1, and COX-2) were evaluated by western blot; intracellular Ca⺲ levels were evaluated with Fluo-4AM; collagen secretion was measured in the culture media using the picrosirius red assay kit. RESULTS: B2R, iNOS, COX-1 and low levels of B1R but not eNOS, were detected by western blot in CF. Also, B1R, B2R, and COX-2 but not iNOS, eNOS or COX-1, were detected by western blot in CMF. By immunocytochemistry, our results showed lower intracellular B1R levels in CF and higher B1R levels in CMF, mainly localized on the cell membrane. Additionally, we found B1R only in CMF cellular membrane through radioligand displacement assay. Bradykinin (BK) B2R agonist increased intracellular Ca²âº levels and reduced collagen secretion both in CF and CMF. These effects were blocked by HOE-140, and inhibited by L-NAME, 1400 W and indomethacin. Des-Arg-kallidin (DAKD) B1R agonist did not increase intracellular Ca²âº levels in CF; however, after preincubation for 1h with DAKD and re-stimulation with the same agonist, we found a low increase in intracellular Ca²âº levels. Finally, DAKD increased intracellular Ca²âº levels and decreased collagen secretion in CMF, being this effect blocked by the B1R antagonist des-Arg9-Leu8-kallidin and indomethacin, but not by L-NAME or 1400 W. CONCLUSION: B1R, B2R, iNOS and COX-1 were expressed differently between CF and CMF, and collagen secretion was regulated differentially by kinin receptor agonists in cultured CF and CMF.
Asunto(s)
Colágeno/metabolismo , Fibroblastos/metabolismo , Miocardio/citología , Miocardio/metabolismo , Miofibroblastos/metabolismo , Receptores de Bradiquinina/metabolismo , Animales , Unión Competitiva/fisiología , Western Blotting , Calcio/metabolismo , Señalización del Calcio/fisiología , Inhibidores de la Ciclooxigenasa/farmacología , Inmunohistoquímica , Calidina/análogos & derivados , Calidina/farmacología , Cininas/metabolismo , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Prostaglandina-Endoperóxido Sintasas/metabolismo , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Receptor de Bradiquinina B1/agonistas , Receptor de Bradiquinina B1/metabolismo , Receptor de Bradiquinina B2/agonistas , Receptor de Bradiquinina B2/metabolismo , Receptores de Bradiquinina/agonistas , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
INTRODUCTION: Biological fluids of cancer patients contain increased levels of kinins. Activation of kinin B1 and B2 receptors expressed on cancer cells produce an increase in cell proliferation, migration of tumor cells and release of MMPs, which are cellular and molecular events of primary importance for tumor growth. The effects of kinins on tumor cells may be amplified by stimulation of kinin receptors expressed on other cells, within the tumor microenvironment, which may in turn increase tumor growth. AREAS COVERED: This review provides a comprehensive discourse on kinins and their receptors in human neoplasia. Concepts that view kinin receptors as targets for human cancer are explored, whilst the molecular basis by which the new dimerized kinin receptor antagonists produce arrest of cell proliferation and apoptosis of cancer cells is also examined. Finally, the role of kinin receptor antagonists as therapeutic tools against human neoplasia is analyzed. EXPERT OPINION: At the present time the available potent, dimerized kinin peptide antagonists, are either specific for B1 or B2 receptors, or are effective on both receptor types. The novel approach of using kinin receptor antagonists either alone or in combination therapy will play a definitive role in the treatment of cancer.
Asunto(s)
Neoplasias/metabolismo , Receptores de Bradiquinina/metabolismo , Animales , Antineoplásicos/farmacología , Antagonistas de los Receptores de Bradiquinina , Humanos , Cininas/metabolismo , Neoplasias/tratamiento farmacológicoRESUMEN
BACKGROUND: Multiple sclerosis (MS) is a demyelinating and neuroinflammatory disease of the human central nervous system (CNS). The expression of kinins is increased in MS patients, but the underlying mechanisms by which the kinin receptor regulates MS development have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Experimental autoimmune encephalomyelitis (EAE) was induced in female C57BL/6 mice by immunization with MOG(35-55) peptide emulsified in complete Freund's adjuvant and injected with pertussis toxin on day 0 and day 2. Here, we report that blockade of the B(1)R in the induction phase of EAE markedly suppressed its progression by interfering with the onset of the immune response. Furthermore, B(1)R antagonist suppressed the production/expression of antigen-specific T(H)1 and T(H)17 cytokines and transcription factors, both in the periphery and in the CNS. In the chronic phase of EAE, the blockade of B(1)R consistently impaired the clinical progression of EAE. Conversely, administration of the B(1)R agonist in the acute phase of EAE suppressed disease progression and inhibited the increase in permeability of the blood-brain barrier (BBB) and any further CNS inflammation. Of note, blockade of the B(2)R only showed a moderate impact on all of the studied parameters of EAE progression. CONCLUSIONS/SIGNIFICANCE: Our results strongly suggest that kinin receptors, mainly the B(1)R subtype, play a dual role in EAE progression depending on the phase of treatment through the lymphocytes and glial cell-dependent pathways.
Asunto(s)
Encefalomielitis Autoinmune Experimental/complicaciones , Encefalomielitis Autoinmune Experimental/patología , Inflamación/patología , Inflamación/prevención & control , Receptores de Bradiquinina/metabolismo , Médula Espinal/patología , Animales , Antagonistas de los Receptores de Bradiquinina , Linfocitos T CD4-Positivos/inmunología , Enfermedad Crónica , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Eliminación de Gen , Humanos , Inflamación/complicaciones , Tejido Linfoide/inmunología , Tejido Linfoide/patología , Ratones , Ratones Endogámicos C57BL , Modelos Biológicos , Vaina de Mielina/metabolismo , Médula Espinal/metabolismo , Células TH1/inmunología , Células Th17/inmunologíaRESUMEN
The carotid artery has a pivotal role in the body since it supplies the head and neck with oxygenated blood. Alterations in the functional and structural integrity of these vessels can decrease blood flow to the brain. For this reason, it is important to understand how the carotid artery responds to various stimuli. The organ bath is a traditional experimental set-up that has been used extensively to investigate the (patho)physiology and pharmacology of in vitro tissue preparations including the rat carotid artery. Molecular biology developed from related fields such as biochemistry, genetics and biophysics is now considered an important tool for understanding physiological pathways in a variety of tissues. Several local and systemic factors regulate carotid reactivity, including vaso-active peptides, such as endothelin 1 (ET-1), angiotensin II (Ang II) and bradykinin (BK). These vaso-active peptides play a fundamental role in controlling the functional and structural integrity of the arterial wall and may be important in physiological processes and in pathological mechanisms underlying vascular diseases. In the rat carotid, these peptides induce vasoconstriction or relaxation by the release of endothelium-derived relaxing factors, such as nitric oxide and prostacyclin. Identification of such signal transduction processes is essential for understanding the mechanisms that regulate vascular smooth muscle cell function, both physiologically and pathophysiologically. The present review discusses the mechanisms of action, distribution of ET-1, Ang II and BK and their receptors in the rat carotid. With this purpose, data obtained in functional studies using classical pharmacological approaches as well as data obtained in molecular biology experiments are discussed.
Asunto(s)
Angiotensina II/metabolismo , Bradiquinina/metabolismo , Arterias Carótidas/metabolismo , Endotelina-1/metabolismo , Animales , Arterias Carótidas/fisiopatología , Endotelio Vascular/metabolismo , Ratas , Receptor de Endotelina A/metabolismo , Receptores de Angiotensina/metabolismo , Receptores de Bradiquinina/metabolismo , Transducción de SeñalRESUMEN
BACKGROUND AND PURPOSE: We investigated the mechanisms underlying the pruritogenic response induced by trypsin in mice, to assess the relevance of neurogenic inflammation components in this response. EXPERIMENTAL APPROACH: Itching was induced by an intradermal injection of trypsin in the mouse neck. The animals were observed for 40 min and their scratching behaviour was quantified. KEY RESULTS: Trypsin-induced itching was blocked by the lima bean trypsin inhibitor, the selective proteinase-activated receptor-2 (PAR-2) antagonist FSLLRY and PAR-2 receptor desensitization. An important involvement of mast cells was observed, as chronic pretreatment with the mast cell degranulator compound 48/80 or the mast cell stabilizer disodium cromoglycate prevented scratching. Also, trypsin response was inhibited by the selective COX-2 inhibitor celecoxib and by the selective kinin B2 (FR173657) and B1 (SSR240612) receptor antagonists. Moreover, an essential role for the mediators of neurogenic inflammation was established, as the selective NK1 (FK888), NK3 (SR142801) and calcitonin gene-related peptide (CGRP(8-37) fragment) receptor antagonists inhibited trypsin-induced itching. Similarly, blockade of transient receptor potential vanilloid 1 (TRPV1) receptors by the selective TRPV1 receptor antagonist SB366791, or by genetic deletion of TRPV1 receptor reduced this behaviour in mice. C-fibre desensitization showed a very similar result. CONCLUSIONS AND IMPLICATIONS: Trypsin intradermal injection proved to be a reproducible model for the study of itching and the involvement of PAR-2 receptors. Also, trypsin-induced itching seems to be widely dependent on neurogenic inflammation, with a role for TRPV1 receptors. In addition, several other mediators located in the sensory nerves and skin also seem to contribute to this process.