The Role of Kinin Receptors in Preventing Neuroinflammation and Its Clinical Severity during Experimental Autoimmune Encephalomyelitis in Mice

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.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa de Apoio aos Nucleos de Excelencia (PRONEX), BrazilFundacaode Apoio a Pesquisa Cientifica Tecnologica do Estado de Santa Catarina (FAPESC), BrazilUniv Fed Santa Catarina, Dept Pharmacol, Ctr Biol Sci, Florianopolis, SC, BrazilUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilWeb of Scienc

Chronic Overexpression of Bradykinin in Kidney Causes Polyuria and Cardiac Hypertrophy

Acute intra-renal infusion of bradykinin increases diuresis and natriuresis via inhibition of vasopressin activity. However, the consequences of chronically increased bradykinin in the kidneys have not yet been studied. A new transgenic animal model producing an excess of bradykinin by proximal tubular cells (KapBK rats) was generated and submitted to different salt containing diets to analyze changes in blood pressure and other cardiovascular parameters, urine excretion, and composition, as well as levels and expression of renin-angiotensin system components. Despite that KapBK rats excrete more urine and sodium, they have similar blood pressure as controls with the exception of a small increase in systolic blood pressure (SBP). However, they present decreased renal artery blood flow, increased intrarenal expression of angiotensinogen, and decreased mRNA expression of vasopressin V1A receptor (AVPR1A), suggesting a mechanism for the previously described reduction of renal vasopressin sensitivity by bradykinin. Additionally, reduced heart rate variability (HRV), increased cardiac output and frequency, and the development of cardiac hypertrophy are the main chronic effects observed in the cardiovascular system. In conclusion: (1) the transgenic KapBK rat is a useful model for studying chronic effects of bradykinin in kidney; (2) increased renal bradykinin causes changes in renin angiotensin system regulation; (3) decreased renal vasopressin sensitivity in KapBK rats is related to decreased V1A receptor expression; (4) although increased renal levels of bradykinin causes no changes in mean arterial pressure (MAP), it causes reduction in HRV, augmentation in cardiac frequency and output and consequently cardiac hypertrophy in rats after 6 months of age

Atherosclerosis severity in patients with familial hypercholesterolemia: the role of T and B lymphocytes

Background and aims Familial hypercholesterolemia (FH) is characterized by lifelong exposure to high LDL-c concentrations and premature atherosclerotic cardiovascular disease; nevertheless, disease severity can be heterogeneous. We aimed at evaluating if the immune-inflammatory system could modulate atherosclerosis burden in FH. Methods From a cohort of subjects with confirmed FH (Dutch Lipid Clinic Network and genotype), 92 patients receiving high-intensity lipid-lowering therapy (statin ± ezetimibe) were included. The extension and severity of coronary atherosclerosis was assessed by standardized reporting systems (CAD-RADS) for coronary computed tomography angiography (CCTA) and coronary artery calcium (CAC) scores. Lipids, apolipoproteins, anti-oxLDL and anti-apolipoprotein B-D peptide (anti-ApoB-D) autoantibodies (IgM and IgG), lymphocytes subtypes, platelet, monocyte and endothelial microparticles (MP), IgM levels (circulating or produced by B1 cells) and cytokines in the supernatant of cultured cells were determined. Multiple linear regression models evaluated associations of these biomarkers with CAC and CAD-RADS scores. Results In univariate analysis CAC correlated with age, systolic blood pressure, TCD4+ cells, and titers of IgM anti-ApoB-D. In multiple linear regression [ANOVA F = 2.976; p = 0.024; R2 = 0.082), CD4+T lymphocytes (B = 35.289; beta = 0.277; p = 0.010; 95%CI for B 8.727 to 61.851), was independently associated with CAC. CAD-RADS correlated with age, systolic blood pressure, titers of IgM anti-ApoB-D, and endothelial MP in univariate analysis. In multiple linear regression, [ANOVA F = 2.790; p = 0.032; R2 = 0.119), only age (B = 0.027; beta = 0.234; p = 0.049; 95% CI for B 0.000 to 0.053) was independent predictor. Conclusions In subjects with FH, under high-intensity lipid-lowering therapy, age and CD4+T cells were associated to atherosclerosis burden

Reduced nerve injury-induced neuropathic pain in kinin B-1 receptor knock-out mice

Injury to peripheral nerves often results in a persistent neuropathic pain condition that is characterized by spontaneous pain, allodynia, and hyperalgesia. Nerve injury is accompanied by a local inflammatory reaction in which nerve-associated and immune cells release several pronociceptive mediators. Kinin B-1 receptors are rarely expressed in nontraumatized tissues, but they can be expressed after tissue injury. Because B-1 receptors mediate chronic inflammatory painful processes, we studied their participation in neuropathic pain using receptor gene-deleted mice. in the absence of neuropathy, we found no difference in the paw-withdrawal responses to thermal or mechanical stimulation between B-1 receptor knock-out mice and 129/J wild-type mice. Partial ligation of the sciatic nerve in the wild-type mouse produced a profound and long-lasting decrease in thermal and mechanical thresholds in the paw ipsilateral to nerve lesion. Threshold changed neither in the sham-operated animals nor in the paw contralateral to lesion. Ablation of the gene for the B-1 receptor resulted in a significant reduction in early stages of mechanical allodynia and thermal hyperalgesia. Furthermore, systemic treatment with the B-1 selective receptor antagonist des-Arg(9)-[Leu(8)]-bradykinin reduced the established mechanical allodynia observed 7-28d after nerve lesion in wild-type mice. Partial sciatic nerve ligation induced an upregulation in B-1 receptor mRNA in ipsilateral paw, sciatic nerve, and spinal cord of wild-type mice. Together, kinin B-1 receptor activation seems to be essential to neuropathic pain development, suggesting that an oral-selective B-1 receptor antagonist might have therapeutic potential in the management of chronic pain.Univ Fed Santa Catarina, Dept Pharmacol, Ctr Biol Sci, BR-88049900 Florianopolis, SC, BrazilEscola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilUniv Mogi Cruzes, BR-0878091 Mogi Das Cruzes, BrazilMax Delbruck Ctr Mol Med, D-13125 Berlin, GermanyEscola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilWeb of Scienc

The role of kinin B-1 receptors in the nociception produced by peripheral protein kinase C activation in mice

The peripheral injection of phorbol myristate acetate (PMA) into the mouse paw induces nociception mediated through activation of protein kinase C (PKC). in the present study, we examine the contribution of kinin B I receptor to PMA-induced nociception. Nociception was assessed after intraplantar injection of PMA or the B-1 receptor agonist des-Arg(9)-bradykinin in mice. Mechanisms of nociception were studied using the combination of knockout mice, selective drugs, and measurement of B-1 receptor mRNA and protein levels. Peripheral injection of PMA (50 pmol/paw) induced a nociceptive behaviour that was abolished by selective B I receptor antagonist des-Arg9-Leu8-bradykinin or by the B-1 receptor gene deletion. Moreover, PMA treatment did not alter B-1 receptor rnRNA levels, but greatly increased B-1 receptor protein levels in the mouse paw. the injection of des-Arg9-bradykinin did not cause nociception in naive mice, but produced marked nociception in animals previously treated with a low dose of PMA (0.5 nmol/paw). the co-treatment of PMA with selective PKC or protein synthesis inhibitors, but not with p38 mitogen activated protein kinase (MAPK) or transcription inhibitors significantly reduced des-Arg(9)-bradykinin-induced nociception. On the other hand, the co-administration of selective PKC or p38 MAPK inhibitors, but not of protein synthesis or transcription inhibitors, reduced des-Arg9-bradykinin-induced nociception when evaluated in PMA pre-injected animals. These results suggest that the B 1 receptor exerts a critical role in the nociception caused by PKC activation in peripheral tissues. Since the PKC pathway is downstream of several pro-inflammatory mediators, B, receptor stimulation appears to contribute to the acute inflammatory pain process. (c) 2007 Elsevier B.V. All rights reserved.Univ Fed Santa Catarina, Dept Pharmacol, Florianopolis, SC, BrazilUniv Fed Santa Maria, Dept Chem, BR-97119900 Santa Maria, RS, BrazilUniv Fed Parana, Dept Pharmacol, BR-80060000 Curitiba, Parana, BrazilMax Delbruck Ctr Mol Med, Berlin, GermanyEscola Paulista Med, Dept Biophys, São Paulo, BrazilEscola Paulista Med, Dept Biophys, São Paulo, BrazilWeb of Scienc

The role of kinin B-1 and B-2 receptors in the persistent pain induced by experimental autoimmune encephalomyelitis (EAE) in mice: Evidence for the involvement of astrocytes

Multiple sclerosis (MS) is a progressive, demyelinating inflammatory disease of the human central nervous system (CNS). While the primary symptoms of MS affect motor function, it is now recognized that chronic pain is a relevant symptom that affects both animals and MS patients. There is evidence that glial cells, such as astrocytes, play an important role in the development and maintenance of chronic pain. Kinins, notably bradykinin (BK) acting through B-1 (B1R) and B-2 (B2R) receptors, play a central role in pain and inflammatory processes. However, it remains unclear whether kinin receptors are involved in neuropathic pain in MS. Here we investigated by genetic and pharmacological approaches the role of kinin receptors in neuropathic pain behaviors induced in the experimental autoimmune encephalomyelitis (EAE) mouse model. Our results showed that gene deletion or antagonism of kinin receptors, especially B1R, significantly inhibited both tactile and thermal hypersensitivity in EAE animals. By contrast, animals with EAE and treated with a B1R selective agonist displayed a significant increase in tactile hypersensitivity. We also observed a marked increase in B1R mRNA and protein level in the mouse spinal cord 14 days after EAE immunization. Blockade of B1R significantly suppressed the levels of mRNAs for IL-17, IFN-gamma, IL-6, CXCL-1/KC, COX-2 and NOS2, as well as glial activation in the spinal cord. of note, the selective B-1 antagonist DALBK consistently prevented IFN-induced up-regulation of TNF-alpha and IL-6 release in astrocyte culture. Finally, both B1R and B2R antagonists significantly inhibited COX-2 and NOS2 expression in primary astrocyte culture. the B1R was co-localized with immunomarker of astrocytes in the spinal cord of EAE-treated animals. the above data constitute convincing experimental evidence indicating that both kinin receptors, especially the B-1 subtype, exert a critical role in the establishment of persistent hypersensitivity observed in the EAE model, an action that seems to involve a central inflammatory process, possibly acting on astrocytes. Thus, B-1 selective antagonists or drugs that reduce kinin release may have the potential to treat neuropathic pain in patients suffering from MS. (C) 2013 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa de Apoio aos Nucleos de Excelencia (PRONEX) of BrazilFundacao de Apoio a Pesquisa do Estado de Santa Catarina (FAPESC) of BrazilUniv Fed Santa Catarina, Lab Autoimunidade & Imunofarmacol, BR-88900000 Ararangua, SC, BrazilUniv Fed Santa Catarina, Ctr Biol Sci, Dept Pharmacol, BR-88040970 Florianopolis, SC, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilWeb of Scienc

Neuropathic pain-like behavior after brachial plexus avulsion in mice: the relevance of kinin B-1 and B-2 receptors

The relevance of kinin B-1 (B1R) and B-2 (B2R) receptors in the brachial plexus avulsion (BPA) model was evaluated in mice, by means of genetic and pharmacological tools. BPA-induced hypernociception was absent in B1R, but not in B2R, knock-out mice. Local or intraperitoneal administration of the B2R antagonist Hoe 140 failed to affect BPA-induced mechanical hypernociception. Interestingly, local or intraperitoneal treatment with B1R antagonists, R-715 or SSR240612, dosed at the time of surgery, significantly reduced BPA-evoked mechanical hypernociception. Intrathecal or intracerebroventricular administration of these antagonists, at the surgery moment, did not prevent the hypernociception. Both antagonists, dosed by intraperitoneal or intrathecal routes (but not intracerebroventricularly) 4 d after the surgery, significantly inhibited the mechanical hypernociception. At 30 d after the BPA, only the intracerebroventricular treatment effectively reduced the hypernociception. A marked increase in B1R mRNA was observed in the hypothalamus, hippocampus, thalamus, and cortex at 4 d after BPA and only in the hypothalamus and cortex at 30 d. in the spinal cord, a slight increase in B1R mRNA expression was observed as early as at 2 d. Finally, an enhancement of B1R protein expression was found in all the analyzed brain structures at 4 and 30d after the BPA, whereas in the spinal cord, this parameter was augmented only at 4d. the data providenewevidence on the role of peripheral and central kinin B1R in the BPA model of neuropathic pain. Selective B1R antagonists might well represent valuable tools for the management of neuropathic pain.Univ Fed Santa Catarina, Dept Pharmacol, Ctr Biol Sci, BR-88049900 Florianopolis, SC, BrazilPontificia Univ Catolica Rio Grande do Sul, Sch Dent, BR-90169900 Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023900 São Paulo, BrazilWeb of Scienc

Leucurogin and melanoma therapy

Leucurogin is an ECD disintegrin-like protein, cloned from Bothrops leucurus venom gland. This new protein, encompassing the disintegrin region of a PIII metalloproteinase, is produced by recombinant technology and its biological and functional activity was partially characterized in this study. Biological activity was characterized in vitro using human fibroblasts. Functional activity of leucurogin was analysed in vitro and in vivo with murine B16F10 Nex-2 and human melanoma BLM cells. The results show that leucurogin inhibits cellular processes dependent on collagen type I. In a competition assay with collagen, leucurogin inhibits, in a dose-dependent manner, the adhesion of fibroblast to collagen. At 10 mu M leucurogin reduces adhesion (40%) and migration (70%) of hFb and inhibits migration (32%) and proliferation (65%) of BLM cells. At 2.5 mu M leucurogin inhibits 80% cell proliferation of B16F10 Nex-2 melanoma cells. At 4.8 mu M leucurogin inhibits, in vitro, the vascular structures formation by endothelial cells by 66%. Leucurogin, injected intraperitoneally, i.p. (5 mu g/animal, two-month old C57/B16 male mice) on alternate days for 15 days, inhibits lung metastasis of Bl6F10 Nex-2 cells by 70-75%. In the treatment of human melanoma, grafted intradermally in the nude mice flank, leucurogin (7.5 mu g/ kg in alternate days during 17 days) inhibits tumor growth by more than 40%. Leucurogin can be considered a promising agent for melanoma treatment