Associations Between Plasma Kinin B1 Receptor Levels and the Presence and Severity of Coronary Artery Disease.

AIM: Kinin B1 receptor (KB1R) was shown to be up-regulated in human carotid atherosclerotic lesions. Serum KB1R levels were also reported to be high in patients with stroke. However, KB1R deficiency increased atherosclerotic lesions. Therefore, the role of KB1R in atherosclerosis remains unclear. Moreover, no study has reported blood KB1R levels in patients with coronary artery disease (CAD). METHODS: We measured plasma KB1R levels in 375 patients undergoing coronary angiography. The severity of CAD was represented as the numbers of ＞50% stenotic vessels and segments and the severity score. RESULTS: CAD was found in 197 patients, of whom 89 had 1-vessel disease (1-VD), 62 had 2-VD, and 46 had 3-VD. Plasma KB1R levels were higher in 197 patients with CAD than in 178 without CAD (median 83.3 vs. 73.7 pg/mL, p＜0.01). A stepwise increase in KB1R levels was found depending on the number of stenotic vessels: 77.1 in 1-VD, 87.8 in 2-VD, and 88.5 pg/mL in 3-VD (p＜0.025). A high KB1R level (＞90.0 pg/mL) was present in 30% of patients with CAD(-), 39% of 1-VD, 50% of 2-VD, and 48% of 3-VD (p＜0.025). KB1R levels correlated with the number of stenotic segments and the severity score (r=0.14 and r=0.17, p＜0.01). In multivariate analysis, KB1R levels were an independent factor associated with CAD. Odds ratio for CAD was 1.62 (95%CI=1.02-2.58) for high KB1R level ＞90.0 pg/mL. CONCLUSION: Plasma KB1R levels in patients with CAD were high and were associated with the presence and severity of CAD independent of atherosclerotic risk factors.

Microvesicle transfer of kinin B1-receptors is a novel inflammatory mechanism in vasculitis.

During vasculitis, activation of the kinin system induces inflammation, whereby the kinin B1-receptor is expressed and activated after ligand binding. Additionally, activated blood cells release microvesicles into the circulation. Here we determined whether leukocyte-derived microvesicles bear B1-kinin receptors during vasculitis, and if microvesicles transfer functional B1-receptors to recipient cells, thus promoting inflammation. By flow cytometry, plasma from patients with vasculitis were found to contain high levels of leukocyte-derived microvesicles bearing B1-receptors. Importantly, renal biopsies from two patients with vasculitis showed leukocyte-derived microvesicles bearing B1-receptors docking on glomerular endothelial cells providing in vivo relevance. Microvesicles derived from B1-receptor-transfected human embryonic kidney cells transferred B1-receptors to wild-type human embryonic kidney cells, lacking the receptor, and to glomerular endothelial cells. The transferred B1-receptors induced calcium influx after B1-receptor agonist stimulation: a response abrogated by a specific B1-receptor antagonist. Microvesicles derived from neutrophils also transferred B1-receptors to wild-type human embryonic kidney cells and induced calcium influx after stimulation. Thus, we found a novel mechanism by which microvesicles transfer functional receptors and promote kinin-associated inflammation.

Effect of Bushenwenyanghuayu decoction on nerve growth factor and bradykinin/bradykinin B1 receptor in a endometriosis dysmenorrhea mouse model.

OBJECTIVE: To observe the effects of Bushenwenyanghuayu decoction (BD), a Traditional Chinese Medicine (TCM), on the serum concentration of nerve growth factor (NGF) and bradykinin (BK), and protein and mRNA levels of NGF and bradykinin B1 receptor (BKB1R) in a mouse model of endometriosis dysmenorrhea. METHODS: Seventy-five experimental female BALB/c mice were randomly divided into five groups, 15 mice each: sham, model, BD high dose (61.67 g/kg), BD low dose (15.42 g/kg), and gestrinone (0.4 mg/kg) groups. All the mice except for those in the sham group underwent auto-transplantation surgery and were gavaged estradiol valerate (0.5 mg/kg, daily for 12 days) after surgery. On the 12th day, 1 h after administration, writhing response was induced by intraperitoneal injection of oxytocin at 2 U/mouse. The writhing frequency and latency were recorded and the volume of the ectopic foci was measured. The concentration of serum NGF and BK was detected by enzyme-linked immunosorbent assay, the protein expression of NGF and BKB1R was tested by immunohistochemistry and western blotting, and NGF and BKB1R mRNAs were detected by real-time PCR. RESULTS: Compared with the model group, the volume of the ectopic foci in the treatment groups was significantly lower (P < 0.01), the writhing frequency was decreased (P < 0.05), and the writhing latency was prolonged (P < 0.01). Compared with the sham group, serum NGF and BK levels in the model group were significantly increased (P < 0.01). There were positive correlations for writhing frequency among the NGF and BK groups (P < 0.01). The serum NGF and BK levels were significantly lower in the treatment groups than the model group (P < 0.05). The protein expression of NGF, BKB1R was significantly decreased in the treatment groups compared with the model group (P < 0.01). NGF and BKB1R mRNA expression was significantly decreased in the treatment groups compared with the model group (P < 0.01). CONCLUSION: NGF and BK/BKB1R may play an important role in the development of endometriosis-associated dysmenorrhea, and BD was found to inhibit the development of endometriosis and relieve dysmenorrhea by influencing NGF and BK/ BKB1R mRNA and protein levels.

Expression of genes encoding kinin receptors in peripheral blood mononuclear cells from patients with acute coronary syndromes.

BACKGROUND: Inflammation plays a critical role in all stages of atherogenesis, including plaque destabilization leading to the rupture and local thrombosis, clinically manifested as unstable angina (UA) or myocardial infarction (MI). Recent data report enhanced expression of numerous pro-inflammatory genes in patients with acute coronary syndrome (ACS) both in plaque and in inflammatory cells. Kinins are peptides involved in vasodilation, vascular permeability, pain and inflammation. Their effects are mediated by two receptors, B1 and B2. As the role of kinins in ACS is not clear, the aim of the study was to assess the expression of the genes encoding kinin receptors in patients with ACS. METHODS: The study was carried out on 40 patients with ACS and 10 age-matched healthy subjects (control (C)). To evaluate gene expression of B1 and B2 kinin receptors, total mRNA was extracted from peripheral blood mononuclear cells and the number of mRNA copies was assessed by quantitative reverse transcriptase-polymerase chain reaction. RESULTS: In patients with MI and UA, the B1 receptor (B1R)/B2 receptor (B2R) ratio was inversed compared with healthy subjects (C group) (MI vs C: 1.54 +/- 0.39 vs 0.36 +/- 0.04; P < 0.01; UA vs C: 2.13 +/- 0.98 vs 0.36 +/- 0.04; P < 0.05 respectively). B2R gene mRNA level was markedly lower in MI group versus C group (24 216 +/- 5409 copies/microg vs 39 908 +/- 5309 copies/microg; P < 0.05). The difference in B1R gene expression between MI and C group was negligible. We have not observed differences in studied genes expression between UA and C groups. CONCLUSION: Patients with ACS show inverted B1R/B2R ratio. Such disturbance in kinin signalling may reflect increased activation of circulating mononuclears, which are important participants of atherosclerotic plaque development and eventually rupture.