Bradykinin B2 Research Articles

Bradykinin induces peripheral antinociception in PGE2-induced hyperalgesia in mice

BackgroundBradykinin (BK) is an endogenous peptide involved in vascular permeability and inflammation. It has opposite effects (inducing hyperalgesia or antinociception) when administered directly in the central nervous system. The aim of this study was to evaluate whether BK may also present this dual effect when injected peripherally in a PGE2-induced nociceptive pain model, as well as to investigate the possible mechanisms of action involved in this event in mice. MethodsMale Swiss and C57BL/6 knockout mice for B1 or B2 bradykinin receptors were submitted to a mechanical paw pressure test and hyperalgesia was induced by intraplantar prostaglandin E2 (2 µg/paw) injection. ResultsBradykinin (20, 40 and 80 ng/paw) produced dose-dependent peripheral antinociception against PGE2-induced hyperalgesia. This effect was antagonized by bradyzide (8, 16 and 32 μg/paw), naloxone (12.5, 25 and 50 μg/paw), nor-binaltorphimine (50, 100 and 200 μg/paw) and AM251 (20, 40 and 80 μg/paw). Bestatin (400 µg/paw), MAFP (0.5 µg/paw) and VDM11 (2.5 µg/paw) potentiated the antinociception of a lower 20 ng BK dose. The knockout of B1 or B2 bradykinin receptors partially abolished the antinociceptive action of BK (80 ng/paw), bremazocine (1 μg/paw) and anandamide (40 ng/paw) when compared with wild-type animals, which show complete antinociception with the same dose of each drug. ConclusionThe present study is the first to demonstrate BK-induced antinociception in peripheral tissues against PGE2-induced nociception in mice and the involvement of κ-opioid and CB1 cannabinoid receptors in this effect.

COVID-19 and Lung Mast Cells: The Kallikrein-Kinin Activation Pathway.

Mast cells (MCs) have relevant participation in inflammatory and vascular hyperpermeability events, responsible for the action of the kallikrein–kinin system (KKS), that affect patients inflicted by the severe form of COVID-19. Given a higher number of activated MCs present in COVID-19 patients and their association with vascular hyperpermeability events, we investigated the factors that lead to the activation and degranulation of these cells and their harmful effects on the alveolar septum environment provided by the action of its mediators. Therefore, the pyroptotic processes throughout caspase-1 (CASP-1) and alarmin interleukin-33 (IL-33) secretion were investigated, along with the immunoexpression of angiotensin-converting enzyme 2 (ACE2), bradykinin receptor B1 (B1R) and bradykinin receptor B2 (B2R) on post-mortem lung samples from 24 patients affected by COVID-19. The results were compared to 10 patients affected by H1N1pdm09 and 11 control patients. As a result of the inflammatory processes induced by SARS-CoV-2, the activation by immunoglobulin E (IgE) and degranulation of tryptase, as well as Toluidine Blue metachromatic (TB)-stained MCs of the interstitial and perivascular regions of the same groups were also counted. An increased immunoexpression of the tissue biomarkers CASP-1, IL-33, ACE2, B1R and B2R was observed in the alveolar septum of the COVID-19 patients, associated with a higher density of IgE+ MCs, tryptase+ MCs and TB-stained MCs, in addition to the presence of intra-alveolar edema. These findings suggest the direct correlation of MCs with vascular hyperpermeability, edema and diffuse alveolar damage (DAD) events that affect patients with a severe form of this disease. The role of KKS activation in events involving the exacerbated increase in vascular permeability and its direct link with the conditions that precede intra-alveolar edema, and the consequent DAD, is evidenced. Therapy with drugs that inhibit the activation/degranulation of MCs can prevent the worsening of the prognosis and provide a better outcome for the patient.

Tissue Kallikrein Protects Rat Prostate against the Inflammatory Damage in a Chronic Autoimmune Prostatitis Model via Restoring Endothelial Function in a Bradykinin Receptor B2-Dependent Way.

Objective The aim of this study was to investigate whether tissue kallikrein (KLK1) can protect the prostate from inflammatory damage and the mechanism involved in it. Methods A total of 50 male Wistar rats were used in this study. Initially, 20 rats were sacrificed to obtain the prostate antigen to induce experimental autoimmune prostatitis (EAP), and the remaining 30 rats were randomly divided into 5 experimental groups (normal control group (NC group), NC+KLK1 group (NCK group), EAP group, EAP+KLK1 group (EAPK group), and EAP+KLK1+HOE140 group (EAPKH group); n = 6). It should be explained that KLK1 mainly exerts its biological effects through bradykinin, and HOE140 is a potent and selective bradykinin receptor B2 (BDKRB2) antagonist. EAP was induced by intradermal injection of 15 mg/ml prostate antigen and complete Freund's adjuvant on days 0, 14, and 28. KLK1 was injected via tail vein at a dose of 1.5 × 10−3 PAN U/kg once a day, and HOE140 was administered by intraperitoneal injection at 20 μg/kg once every two days. Rats were sacrificed on day 42. The RNA and protein of the rat prostate were extracted to analyze the expression differences of KLK1, as well as the inflammation-, fibrosis-, and oxidative stress-related genes. The inflammatory cell infiltration and microvessel density of the prostate were also analyzed by pathological examination. In addition, pathological analysis was performed on prostate samples from patients undergoing benign prostate hyperplasia (BPH) surgery. Results The expression of KLK1 in the prostate decreased in the EAP group as well as BPH patients with obvious inflammation. KLK1 administration significantly inhibited inflammatory cell infiltration and reduced the production of inflammatory cytokines in the EAPK group. Prostate samples from the EAP group showed increased infiltration of T cells and macrophages, as well as gland atrophy, hypoxia, fibrosis, and angiogenesis. KLK1 administration upregulated endothelial nitric oxide synthase (eNOS) expression and suppressed oxidative stress, as well as transforming growth factor β1 (TGF-β) signaling pathways and the proangiogenic vascular endothelial growth factor (VEGF) in the EAPK group. However, in the EAPKH group in which HOE140 blocked BDKRB2, the beneficial effects of KLK1 were all cancelled. In addition, KLK1 intervention in normal rats had no obvious side effects. Conclusion The KLK1 expression is inhibited in the inflamed prostates of humans and rats. Exogenous KLK1 restored endothelial function via a BDKRB2-dependent way and then played a role in improving microcirculation and exerted anti-inflammatory, antifibrotic, and antioxidative stress effects in the rat chronic-inflamed prostate.

In vitro pharmacological profile of PHA-022121, a small molecule bradykinin B2 receptor antagonist in clinical development

PHA-022121 is a novel small molecule bradykinin B2 receptor antagonist, in clinical development for the treatment and prevention of hereditary angioedema attacks. The present study describes the in vitro pharmacological characteristics of PHA-022121 and its active metabolite, PHA-022484 (M2-D). In mammalian cell lines, PHA-022121 and PHA-022484 show high affinity for the recombinant human bradykinin B2 receptor with Ki values of 0.47 and 0.70 nM, respectively, and potent antagonism of the human bradykinin B2 receptor with Kb values of 0.15 and 0.26 nM, respectively (calcium mobilization assay). Antagonist potency at the recombinant cynomolgus monkey bradykinin B2 receptor is similarly high (Kb values of 1.42 and 1.12 nM for PHA-022121 and PHA-022484, respectively), however, potency at rat, mouse, rabbit and dog bradykinin B2 receptors is at least 100-fold lower than the potency at the human receptor for both compounds. In the human umbilical vein contractility assay, both PHA-022121 and PHA-022484 show a potent, surmountable and reversible B2 antagonist activity with pA2 values of 0.35 and 0.47 nM, respectively. The in vitro off-target profile of PHA-022121 and PHA-022484 demonstrates a high degree of selectivity over a wide range of molecular targets, including the bradykinin B1 receptor.It is concluded that PHA-022121 is a novel, low-molecular weight, competitive antagonist of the human bradykinin B2 receptor with high affinity, high antagonist potency, and high selectivity. It is about 20-fold more potent than icatibant at the human bradykinin B2 receptor as assessed using recombinant or endogenously expressed receptors.

The Effect of Bromelain (Anaheal) on Clinical and Para-Clinical Parameters in Hospitalized COVID-19 Patients

The severity of COVID-19 disease and its mortality may be due to a localized vascular problem owing to the activation of bradykinin B1 receptors on endothelial cells in the lungs that occur following inflammation. Bromelain acts as an anti-inflammatory factor and can lower the level of bradykinin in the serum and tissues. Patients with the novel coronavirus (COVID-19) referred to Masih Daneshvari Hospital in Tehran were included in the study after providing full explanations and obtaining written consent. The 40 patients with mild to moderate symptoms were randomly divided into the control group (No: 20) and sample (No: 20). In the sample group, a dose of 200 mg bromelain was given to patients every 8 hours. In the control group, placebo capsules were administered exactly at the above intervals. Clinical and paraclinical factors (including SaO2, RR body temperature, MAP, HR, CRP, ESR, AST, ALT, Bil, BUN, Cr, WBC, Lymph, LDH, Plt were evaluated on a regular basis for up to five days. The results were evaluated using t-test and SPSS21 software. After treatment, the sample (Bromelain) group indicated significant improvement in SaO2, RR, HR, AST, ALT, BUN, ESR, LDH, and WBC and Lymphocyte count (P<0.05). Other factors did not have a significant difference with the control group. Bromelain causes improvement in some clinical symptoms such as respiratory parameters and para clinical items of mild to moderate hospitalized COVID-19 patients, so it can be a promising treatment. Furthered evaluation of larger groups is recommended.

The Bradykinin B2 Receptor Agonist (NG291) Causes Rapid Onset of Transient Blood-Brain Barrier Disruption Without Evidence of Early Brain Injury.

Background: The blood–brain barrier (BBB) describes the brain’s highly specialized capillaries, which form a dynamic interface that maintains central nervous system (CNS) homeostasis. The BBB supports the CNS, in part, by preventing the entry of potentially harmful circulating molecules into the brain. However, this specialized function is challenging for the development of CNS therapeutics. Several strategies to facilitate drug delivery into the brain parenchyma via disruption of the BBB have been proposed. Bradykinin has proven effective in disrupting mechanisms across the blood–tumor barrier. Unfortunately, bradykinin has limited therapeutic value because of its short half-life and the undesirable biological activity elicited by its active metabolites.Objective: To evaluate NG291, a stable bradykinin analog, with selective agonist activity on the bradykinin-B2 receptor and its ability to disrupt the BBB transiently.Methods: Sprague Dawley rats and CD-1 mice were subjected to NG291 treatment (either 50 or 100 μg/kg, intravenously). Time and dose-dependent BBB disruption were evaluated by histological analysis of Evans blue (EB) extravasation. Transcellular and paracellular BBB leakage were assessed by infiltration of 99mTc-albumin (66.5 KDa) and 14C-sucrose (340 Da) radiolabeled probes into the brains of CD-1 mice treated with NG291. NG291 influence on P-glycoprotein (P-gp) efflux pump activity was evaluated by quantifying the brain accumulation of 3H-verapamil, a known P-gp substrate, in CD-1 mice.Results: NG291-mediated BBB disruption was localized, dose-dependent, and reversible as measured by EB extravasation. 99mTc-albumin leakage was significantly increased by 50 μg/kg of NG291, whereas 100 μg/kg of NG291 significantly augmented both 14C-sucrose and 99mTc-albumin leakage. NG291 enhanced P-gp efflux transporter activity and was unable to increase brain uptake of the P-gp substrate pralidoxime. NG291 did not evoke significant short-term neurotoxicity, as it did not increase brain water content, the number of Fluoro-Jade C positive cells, or astrocyte activation.Conclusion: Our findings strongly suggest that NG291 increases BBB permeability by two different mechanisms in a dose-dependent manner and increases P-gp efflux transport. This increased permeability may facilitate the penetration into the brain of therapeutic candidates that are not P-gp substrates.

Epidemiology and Management of Acquired Angioedema Due to C1 Inhibitor Deficiency

AAE-C1-INH (acquired angioedema owing to C1-inhibitor (C1-INH) deficiency) is a dangerous illness that can lead to asphyxiation due to laryngeal edoema. Only around 1% to 2% of angioedema cases are classified as HAE or AAE, with HAE being 10 times more prevalent than AAE. The sole clinical distinction between HAE and AAE is the age at which symptoms appea, AAE-C1-INH is usually diagnosed after 40 years of age. There is no licensed therapy for AAE-C1-INH at this time. AAE-C1-INH attacks are treated with HAE-C1-INH medicines such plasma-derived C1-INH concentrate (pdC1-INH) and the bradykinin B2 receptor antagonist, icatibant. These on-demand medications are thought to be most helpful when provided early in the attack. However, there is a scarcity of published data on the efficacy and safety of AAE-C1-INH therapies.

Development and Validation of a Six-Gene Prognostic Signature for Bladder Cancer.

Human bladder cancer (BCa) is the most common urogenital system malignancy. Patients with BCa have limited treatment efficacy in clinical practice. Novel biomarkers could provide more crucial information conferring to cancer diagnosis, treatment, and prognosis. Here, we aimed to explore and identify novel biomarkers associated with cancer-specific survival of patients with BCa to build a prognostic signature. Based on univariate Cox regression, Lasso regression, and multivariate Cox regression analysis, we conducted an integrated analysis in the training set (GSE32894) and established a six-gene signature to predict the cancer-specific survival for human BCa. The six genes were Cyclin Dependent Kinase 4 (CDK4), E2F Transcription Factor 7 (E2F7), Collagen Type XI Alpha 1 Chain (COL11A1), Bradykinin Receptor B2 (BDKRB2), Yip1 Interacting Factor Homolog B (YIF1B), and Zinc Finger Protein 415 (ZNF415). Then, we validated the prognostic value of the model by using two other datasets (GSE13507 and TCGA). Also, we conducted univariate and multivariate Cox regression analyses, and results indicated that the six-gene signature was an independent prognostic factor of cancer-specific survival of patients with BCa. Functional analysis was performed based on the differentially expressed genes of low- and high-risk patients, and we found that they were enriched in lipid metabolic and cell division-related biological processes. Meanwhile, the gene set enrichment analysis (GSEA) revealed that high-risk samples were enriched in cell cycle and cancer-related pathways [G2/M checkpoint, E2F targets, mitotic spindle, mTOR signaling, spermatogenesis, epithelial–mesenchymal transition (EMT), DNA repair, PI3K/AKT/mTOR signaling, unfolded protein response (UPR), and MYC targets V2]. Lastly, we detected the relative expression of each signature in BCa cell lines by quantitative real-time PCR (qRT-PCR). As far as we know, currently, the present study is the first research that developed and validated a cancer-specific survival prognostic index based on three independent cohorts. The results revealed that this six-gene signature has a predictive ability for cancer-specific prognosis. Moreover, we also verified the relative expression of these six signatures between the bladder cell line and four BCa cell lines by qRT-PCR. Nevertheless, experiments to further explore the function of six genes are lacking.

Hereditary angioedema due to C1 inhibitor deficiency: real-world experience from the Icatibant Outcome Survey in Spain

BackgroundThe Icatibant Outcome Survey (IOS) is an international registry monitoring the use of icatibant, a bradykinin B2 receptor antagonist indicated for the acute treatment of hereditary angioedema (HAE) attacks. Our goal was to assess disease characteristics and icatibant treatment outcomes in patients with HAE due to C1 inhibitor deficiency (HAE type 1 or 2 (HAE-1/2)) from Spain relative to other countries participating in IOS.MethodsDescriptive retrospective analyses of data are reported from 10 centers in Spain vs 51 centers in 12 other participating countries (July 2009 to January 2019).ResultsNo meaningful differences were identified between patients in Spain (n = 119) and patients across other countries (n = 907) regarding median age at symptom onset (15.0 vs 12.0 years) or diagnosis (22.3 vs 20.5 years). Overall HAE attack rates (total attacks/total years of follow-up) were 2.66 in Spain and 1.46 across other countries. Patients in Spain reported fewer severe/very severe HAE attacks before treatment (41.0% vs 45.9%; P < 0.0001) and, for icatibant-treated attacks, longer median time to treatment (2.9 vs 1.0 h), time to attack resolution (18.0 vs 5.5 h), and total attack duration (24.6 vs 8.0 h). Use of androgens for long-term prophylaxis was higher in Spain (51.2% vs 26.7%).ConclusionPatients with HAE-1/2 in Spain reported fewer severe/very severe attacks, administered icatibant later, and had longer-lasting attacks than did patients across other countries in IOS. These differences may indicate varying disease management practices (e.g., delayed icatibant treatment) and reporting. Efforts to raise awareness on the benefits of early on-demand treatment may be warranted.Trial registration: NCT01034969.

Bradykinin Is a Proximal Event in Experimental Cerebral Malaria

Human malaria is a complex disease and a leading cause of mortality in children under 5 years of age. Plasmodium falciparum (Pf) is the agent responsible for cerebral malaria. Parasite infected erythrocytes are sequestered in the brain vasculature, disrupting the blood-brain-barrier, and with systemic inflammation leading to progressive brain edema. The precise pathophysiologic mechanism(s) underlying brain swelling in CM is not known. Recent work from our laboratories indicates that there is a role for bradykinin (BK) in fluid transport in human brain microvascular endothelial cells (Front Med 6:75, 2019).We examined the role of bradykinin (BK) in pediatric CM. Initial studies showed recombinant falcipain-2, a cysteine protease contained in the parasite digestive vacuole, was inhibited by high molecular weight kininogen (HK), with an IC 50=36 nM. Further, falcipain-2, but not the related protease falcipain 3, hydrolyzed the chromogenic substrate S2302 (Pro-Phe-Arg-pNA) at pH 7.4 with an 88 nM K m. These results suggest that falcipain-2 has plasma kallikrein-like activity. HK is both an inhibitor and substrate of falcipain-2. Molar excess HK to falcipain-2 (ratio 8:1 to 2:1) blocked the proteolytic activity of the cysteine protease at pH 7.4. Equal molar falcipain-2 to HK (1:1) resulted in kallikrein-like cleavage of HK with stable BK liberation over 1 h. Molar excess falcipain-2 to HK (1:2 and greater) led to progressive HK cleavage into smaller proteins and peptides. The falcipain-2 major cleavages observed by N-terminal sequencing were in Domain 3 of the heavy chain of HK, the cysteine protease inhibitory region (I 292ASFSQNCDIYPGKDF 303, D 320IPTNSPELEETLT 334, and E 412KKIYPTVNCQPLG 425). P. falciparum trophozoite lysates completely hydrolyzed purified and plasma HK into a ~64 kDa heavy chain and ~46 kDa light chain in buffer containing EDTA, pepstatin, and PMSF. The cysteine proteinase inhibitor E64 blocked this cleavage, suggesting that the relevant activity was that of a cysteine protease.Plasma from Kenyan children presenting with CM (fever, parasitemia, coma) had evidence of circulating cHK, indicative of BK released from HK. Forty percent (8 of 20) of CM patients had no intact 120 kDa HK at hospital entry. In contrast, only 16% (3 of 8) of children with uncomplicated malaria had detectable cHK. In CM patients, the HK level before antimalarial treatment (58 ± 3.9 µg/ml) was significantly lower than the value after clinical recovery (69 ± 3.6 µg/ml; p<0.04) as measured by competitive ELISA. We also examined the roles of BK and HK in experimental cerebral malaria. 10 6 infected red blood cells with P. berghei ANKA were injected intraperitoneally into wild-type (C57BL/6) and total kininogen deficient (kgn1 -/-) C57BL/6 mice. The level of parasitemia on day 5 post-infection was ≥ 8% for both groups of mice (Figure 1). The kgn1 -/- mice had protected neuronal function measured by SHIRPA score relative to wild-type mice. Cerebral edema detected in wild- type mice by Evans Blue dye extravasation test was nearly completely attenuated in kgn1 -/- mice. Corroborative studies were performed in BK B2 receptor deleted (bdkrb2 -/-) mice. In mice with 15% parasitemia for both genotypes, there was significantly less neurologic function deterioration and a 30% reduction in cerebral Evans blue extravasation into brain parenchyma in the bdkrb2 -/- mice.These data strongly suggest that falcipain-2 liberates BK from HK by acting like plasma kallikrein and in high concentrations destroys HK's cysteine protease inhibitory region. Some children with CM have in vivo evidence of prior HK proteolysis. Total kininogen deficiency protects mice from lethal experimental CM. Taken together, these data suggest that bradykinin is a proximal mediator of cerebral malaria. [Display omitted] DisclosuresMcCrae: Dova, Novartis, Rigel, and Sanofi Genzyme: Consultancy; Sanofi, Novartis, Alexion, and Johnson & Johnson: Consultancy, Honoraria.

A modular map of Bradykinin-mediated inflammatory signaling network.

Bradykinin, a member of the kallikrein-kinin system (KKS), is associated with an inflammatory response pathway with diverse vascular permeability functions, including thrombosis and blood coagulation. In majority, bradykinin signals through Bradykinin Receptor B2 (B2R). B2R is a G protein-coupled receptor (GPCR) coupled to G protein family such as Gαqs, Gαq/Gα11, Gαi1, and Gβ1γ2. B2R stimulation leads to the activation of a signaling cascade of downstream molecules such as phospholipases, protein kinase C, Ras/Raf-1/MAPK, and PI3K/AKT and secondary messengers such as inositol-1,4,5-trisphosphate, diacylglycerol and Ca2+ ions. These secondary messengers modulate the production of nitric oxide or prostaglandins. Bradykinin-mediated signaling is implicated in inflammation, chronic pain, vasculopathy, neuropathy, obesity, diabetes, and cancer. Despite the biomedical importance of bradykinin, a resource of bradykinin-mediated signaling pathway is currently not available. Here, we developed a pathway resource of signaling events mediated by bradykinin. By employing data mining strategies in the published literature, we describe an integrated pathway reaction map of bradykinin consisting of 233 reactions. Bradykinin signaling pathway events included 25 enzyme catalysis reactions, 12 translocations, 83 activation/inhibition reactions, 11 molecular associations, 45 protein expression and 57 gene regulation events. The pathway map is made publicly available on the WikiPathways Database with the ID URL: https://www.wikipathways.org/index.php/Pathway:WP5132. The bradykinin-mediated signaling pathway map will facilitate the identification of novel candidates as therapeutic targets for diseases associated with dysregulated bradykinin signaling.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12079-021-00652-0.

Role of nitric oxide, bradykinin B2 receptor, and TRPV1 in the airway alterations caused by simvastatin in rats

Dry cough has been reported in patients receiving statin therapy. However, the underlying mechanism or other possible alterations in the airways induced by statins remain unknown. Thus, the aim of this study was to evaluate whether simvastatin promotes alterations in airways, such as bronchoconstriction and plasma extravasation, as well as the mechanism involved in these events. Using methods to detect alterations in airway resistance and plasma extravasation, we demonstrated that simvastatin [20 mg/kg, intravenous (i.v.)] caused plasma extravasation in the trachea (79.8 + 14.8 μg/g/tissue) and bronchi (73.3 + 8.8 μg/g/tissue) of rats, compared to the vehicle (34.2 + 3.6 μg/g/tissue and 29.3 + 5.3 μg/g/tissue, respectively). NG-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg, intraperitoneal), a nitric oxide (NO) synthase inhibitor, Icatibant [HOE 140, 10 nmol/50 μl, intratracheal (i.t.)], a bradykinin B2 antagonist, and capsazepine (100 nmol/50 μl, i.t.), a TRPV1 antagonist, attenuated simvastatin-induced plasma extravasation. Simvastatin (5, 10 and 20 mg/kg) did not cause bronchoconstriction per se, but exacerbated the bronchoconstrictive response to bradykinin (30 nmol/kg, i.v.), a B2 agonist (0.7 + 0.1 ml/H2O), or capsaicin (30 nmol/kg, i.v.), a TRPV1 agonist (0.8 + 0.1 ml/H2O), compared to the vehicle (0.1 + 0.04 ml/H2O and 0.04 + 0.01 ml/H2O, respectively). The bronchoconstriction elicited by bradykinin (100 nmol/kg, i.v.) in simvastatin non-treated rats was inhibited by L-NAME. The exacerbation of bronchoconstriction induced by bradykinin or capsaicin in simvastatin-treated rats was inhibited by L-NAME, HOE 140 or capsazepine. These results suggest that treatment with simvastatin promotes the release of bradykinin, which, via B2 receptors, releases NO that can then activate the TRPV1 to promote plasma extravasation and bronchoconstriction.

Renin-Angiotensin System Induced Secondary Hypertension: The Alteration of Kidney Function and Structure

Long-term hypertension is known as a major risk factor for cardiovascular and chronic kidney disease (CKD). The Renin-angiotensin system (RAS) plays a key role in hypertension pathogenesis. Angiotensin II (Ang II) enhancement in Ang II-dependent hypertension leads to progressive CKD and kidney fibrosis. In the two-kidney one-clip model (2K1C), more renin is synthesized in the principal cells of the collecting duct than juxtaglomerular cells (JGCs). An increase of renal Ang I and Ang II levels and a decrease of renal cortical and medullary Ang 1–7 occur in both kidneys of the 2K1C hypertensive rat model. In addition, the activity of the angiotensin-converting enzyme (ACE) increases, while ACE2's activity decreases in the medullary region of both kidneys in the 2K1C hypertensive model. Also, the renal prolyl carboxypeptidase (PrCP) expression and its activity reduce in the clipped kidneys. The imbalance in the production of renal ACE, ACE2, and PrCP expression causes the progression of renal injury. Intrarenal angiotensinogen (AGT) expression and urine AGT (uAGT) excretion rates in the unclipped kidney are greater than the clipped kidney in the 2K1C hypertensive rat model. The enhancement of Ang II in the clipped kidney is related to renin secretion, while the elevation of intrarenal Ang II in the unclipped kidney is related to stimulation of AGT mRNA and protein in proximal tubule cells by a direct effect of systemic Ang II level. Ang II-dependent hypertension enhances macrophages and T-cell infiltration into the kidney which increases cytokines, and AGT synthesis in proximal tubules is stimulated via cytokines. Accumulation of inflammatory cells in the kidney aggravates hypertension and renal damage. Moreover, Ang II-dependent hypertension alters renal Ang II type 1 & 2 receptors (AT1R & AT2R) and Mas receptor (MasR) expression, and the renal interstitial fluid bradykinin, nitric oxide, and cGMP response to AT1R, AT2R, or BK B2-receptor antagonists. Based on a variety of sources including PubMed, Google Scholar, Scopus, and Science-Direct, in the current review, we will discuss the role of RAS-induced secondary hypertension on the alteration of renal function.

Changes in the expression level of the genes involved in the innate and adaptive immunity of divers

From time immemorial, humans had engaged in breath-hold diving. Developing the scuba (self-contained underwater breathing apparatus) in the last century has made humans increase the capabilities and efficiency of diving. Shallow diving is usually without side effects, but there may be a series of side effects called Decompression Sickness (DCS), which can even lead to severe neurological damages and death in deep and long dives. Scuba diving and its complications alter the pattern of many genes expression involved in innate and adaptive immunity. Researchers have reported various types of these changes in both the genomes of healthy and sick divers. This study surveyed the ten gene expression levels imported into immune responses like apoptosis and inflammation by real-time PCR in Iranian professional fit divers in steady-state. These genes were: Interleukins (IL-6, IL-8, IL-10), Tumor Necrosis Factor (TNFα), complement C3 (C3α), Tumor Necrosis Factor Receptor Type 1 - Associated Death Domain (TRADD), bradykinin receptor B2 (BDKRB2), rennin (REN), arachidonate 5-lipoxygenase (ALOX5), and prostaglandin-endoperoxide synthase 2 (PTGS2). The results showed that the expression levels of TNFα, ALOX5, TRADD, and interleukin genes increased, but PTGS2, REN, and C3α genes' expression levels did not change much. BDKRB2 gene expression level also decreased.

Pathological AT1R-B2R Protein Aggregation and Preeclampsia.

Preeclampsia is one of the most frequent and severe complications of pregnancy. Symptoms of preeclampsia usually occur after 20 weeks of pregnancy and include hypertension and kidney dysfunction with proteinuria. Up to now, delivery of the infant has been the most effective and life-saving treatment to alleviate symptoms of preeclampsia because a causative treatment does not exist, which could prolong a pregnancy complicated with preeclampsia. Preeclampsia is a complex medical condition, which is attributed to a variety of different risk factors and causes. Risk factors account for insufficient placentation and impaired vasculogenesis and finally culminate in this life-threatening condition of pregnancy. Despite progress, many pathomechanisms and causes of preeclampsia are still incompletely understood. In recent years, it was found that excessive protein complex formation between G-protein-coupled receptors is a common sign of preeclampsia. Specifically, the aberrant heteromerization of two vasoactive G-protein-coupled receptors (GPCRs), the angiotensin II AT1 receptor and the bradykinin B2 receptor, is a causative factor of preeclampsia symptoms. Based on this knowledge, inhibition of abnormal GPCR protein complex formation is an experimental treatment approach of preeclampsia. This review summarizes the impact of pathological GPCR protein aggregation on symptoms of preeclampsia and delineates potential new therapeutic targets.

Human urinary kininogenase reduces the endothelial injury by inhibiting Pyk2/MCU pathway

The injury of endothelial cells is one of the initiating factors in restenosis after endovascular treatment. Human urinary kallidinogenase (HUK) is a tissue kallikrein which is used for ischemia-reperfusion injury treatment. Studies have shown that HUK may be a potential therapeutic agent to prevent stenosis after vascular injury, however, the precise mechanisms have not been fully established. This study is to investigate whether HUK can protect endothelial cells after balloon injury or H2O2-induced endothelial cell damage through the proline-rich tyrosine kinase 2 (Pyk2)/mitochondrial calcium uniporter (MCU) pathway. Intimal hyperplasia, a decrease of pinocytotic vesicles and cell apoptosis were found in the common carotid artery balloon injury and H2O2-induced endothelial cell damage, Pyk2/MCU was also up-regulated in such pathological process. HUK could prevent these injuries partially via the bradykinin B2 receptor by inhibiting Pyk2/MCU pathway, which prevented the mitochondrial damage, maintained calcium balance, and eventually inhibited cell apoptosis. Furthermore, MCU expression was not markedly increased if Pyk2 was suppressed by shRNA technique in the H2O2 treatment group, and cell viability was significantly better than H2O2-treated only. In short, our results indicate that the Pyk2/MCU pathway is involved in endothelial injury induced by balloon injury or H2O2-induced endothelial cell damage. HUK plays an protective role by inhibiting the Pyk2/MCU pathway in the endothelial injury.

Involvement of bradykinin and bradykinin B1 receptor in patients with endometriosis.

Endometriosis (EM), a benign aseptic inflammatory disease, is associated with the presence of endometrial foci. Pain, one of its typical symptoms, has been reported as a constant stressor, but the etiology and pathogenesis of EM-associated pain are unclear. In the present study, eutopic and ectopic endometrium samples from women with EM (n=50) and normal endometrium samples from control subjects (n=20) were collected. Serum levels of prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and bradykinin (BK) were measured using commercial ELISA kits. The expression of the BKB1 receptor (BKB1R) protein was evaluated by immunohistochemical staining and western blot assay. The mRNA expression of BKB1R was measured by reverse transcription-quantitative PCR. The results revealed that there was a substantial increase in the protein and mRNA expression of BKB1R, as well as the release of PGE2, PGF2α and BK in the blood, in the EM group compared with that in the control group. Moreover, PGE2, PGF2α and BK levels were significantly correlated with each other, as well as with the pain intensity of EM. The increased expression levels of BKB1R protein and mRNA were positively correlated with the pain degree of EM. Thus, these data indicated that BK and BKB1R were involved in the pathological onset of EM-associated pain and that they may play an important role in EM-related pain by inducing PGE2 and PGF2α. The data indicate a potential new therapeutic target for EM-related pain.

Recognition and Management of Hereditary Angioedema: Best Practices for Dermatologists.

ObjectiveThe goal of this article is to discuss the importance of differentiating hereditary angioedema (HAE) from other types of angioedema, describe advances in HAE management, especially long-term prophylaxis (LTP), and offer practical recommendations for dermatologists.CommentaryWhile HAE is rare, dermatologists are likely to encounter patients with this condition at some point over the course of their clinical practice due to the fact that HAE episodes typically involve subcutaneous swelling and sometimes erythema marginatum. HAE is characterized by recurrent episodes of painful and/or disabling bradykinin-mediated angioedema. Unfortunately, HAE is commonly mistaken for other conditions such as allergic and other mast cell-mediated angioedema, but has very different treatment requirements. Delayed diagnosis of HAE can result in years of avoidable debilitating symptoms, inappropriate treatment, potentially unnecessary invasive intervention, and reduced quality of life, and can be life threatening. Thus, timely identification of HAE is essential to ensure appropriate clinical management. Patients with HAE have either deficiency or dysfunction of the C1 inhibitor (C1INH) protein that inhibits proteases in the contact, complement, and fibrinolytic systems. Pathway-specific HAE treatments include C1INH replacement, kallikrein inhibitors, and bradykinin receptor antagonists. Treatment options for managing acute attacks include C1INH replacement (plasma-derived or recombinant formulations), icatibant (kallikrein inhibitor), and ecallantide (bradykinin B2 receptor antagonist). In the past 5 years, several new options for LTP have been approved, including a subcutaneous plasma-derived C1INH formulation and two kallikrein inhibitors (lanadelumab; berotralstat). Optimal management of HAE entails the creation of a comprehensive management plan that addresses both acute and long-term patient needs and includes input from an HAE expert and the patient/caregivers.

Mechanism deconvolution of Qing Fei Pai Du decoction for treatment of Coronavirus Disease 2019 (COVID-19) by label-free integrative pharmacology assays

Ethnopharmacological relevanceTraditional Chinese medicine (TCM) has a long history in the prevention and treatment of pandemics. The TCM formula Lung Cleansing and Detoxifying Decoction (LCDD), also known as Qing Fei Pai Du Decoction, has been demonstrated effective against Coronavirus Disease 2019 (COVID-19). Aim of the studyThis work aimed to elucidate the active ingredients, targets and pathway mechanism of LCDD related to suppression of inflammatory, immunity regulation and relaxation of airway smooth muscle for the treatment of COVID-19. Materials and methodsMining chemical ingredients reported in LCDD, 144 compounds covering all herbs were selected and screened against inflammatory-, immunity- and respiratory-related GPCRs including GPR35, H1, CB2, B2, M3 and β2-adrenoceptor receptor using a label-free integrative pharmacology method. Further, all active compounds were detected using liquid chromatography-tandem mass spectrometry, and an herb-compound-target network based on potency and content of compounds was constructed to elucidate the multi-target and synergistic effect. ResultsThirteen compounds were identified as GPR35 agonists, including licochalcone B, isoliquiritigenin, etc. Licochalcone B, isoliquiritigenin and alisol A exhibited bradykinin receptor B2 antagonism activities. Atractyline and shogaol showed as a cannabinoid receptor CB2 agonist and a histamine receptor H1 antagonist, respectively. Tectorigenin and aristofone acted as muscarinic receptor M3 antagonists, while synephrine, ephedrine and pseudoephedrine were β2-adrenoceptor agonists. Pathway deconvolution assays suggested activation of GPR35 triggered PI3K, MEK, JNK pathways and EGFR transactivation, and the activation of β2-adrenoceptor mediated MEK and Ca2+. The herb-compound-target network analysis found that some compounds such as licochalcone B acted on multiple targets, and multiple components interacted with the same target such as GPR35, reflecting the synergistic mechanism of Chinese medicine. At the same time, some low-abundance compounds displayed high target activity, meaning its important role in LCDD for anti-COVID-19. ConclusionsThis study elucidates the active ingredients, targets and pathways of LCDD. This is useful for elucidating multitarget synergistic action for its clinical therapeutic efficacy.

Association of Variants Near the Bradykinin Receptor B2 Gene With Angioedema in Patients Taking ACE Inhibitors

BackgroundAngioedema is a rare but potentially life-threatening adverse reaction associated with angiotensin-converting enzyme (ACE) inhibitors. Identification of potential genetic factors related to this adverse event may help identify at-risk patients. ObjectivesThe aim of this study was to identify genetic factors associated with ACE inhibitor–associated angioedema. MethodsA genomewide association study involving patients of European descent, all taking ACE inhibitors, was conducted in a discovery cohort (Copenhagen Hospital Biobank), and associations were confirmed in a replication cohort (Swedegene). Cases were defined as subjects with angioedema events and filled prescriptions for ACE inhibitors ≤180 days before the events. Control subjects were defined as those with continuous treatment with ACE inhibitors without any history of angioedema. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed for angioedema risk using logistic mixed model regression analysis. Summary statistics from the discovery and replication cohorts were analyzed using a fixed-effects meta-analysis model. ResultsThe discovery cohort consisted of 462 cases and 53,391 ACE inhibitor–treated control subjects. The replication cohort consisted of 142 cases and 1,345 ACE inhibitor–treated control subjects. In the discovery cohort, 1 locus, residing at chromosome 14q32.2, was identified that associated with angioedema at the genomewide significance level of P <5 × 10–8. The lead variant at this locus, rs34485356, is an intergenic variant located 60 kb upstream of BDKRB2 (OR: 1.62; 95% CI: 1.38 to 1.90; P = 4.3 × 10−9). This variant was validated in our replication cohort with a similar direction and effect size (OR: 1.60; 95% CI: 1.13 to 2.25; P = 7.2 × 10−3). We found that carriers of the risk allele had significantly lower systolic (−0.46 mm Hg per T allele; 95% CI: −0.83 to −0.10; P = 0.013) and diastolic (−0.26 mm Hg per T allele; 95% CI: −0.46 to −0.05; P = 0.013) blood pressure. ConclusionsIn this genomewide association study involving individuals treated with ACE inhibitors, we found that common variants located in close proximity to the bradykinin receptor B2 gene were associated with increased risk for ACE inhibitor–related angioedema.