Therapeutic potential of icatibant (HOE-140, JE-049)

Bradykinin protects nucleus pulposus cells from tert-butyl hydroperoxide-induced damage and delays intervertebral disc degeneration

Intervertebral disc degeneration (IVDD) is a leading cause of degenerative spinal disorders, involving complex biological processes. This study investigates the role of the kallikrein-kinin system (KKS) in IVDD, focusing on the protective effects of bradykinin (BK) on nucleus pulposus cells (NPCs) under oxidative stress. Clinical specimens were collected, and experiments were conducted using human and rat primary NPCs to elucidate BK's impact on tert-butyl hydroperoxide (TBHP)-induced oxidative stress and damage. The results demonstrate that BK significantly inhibits TBHP-induced NPC apoptosis and restores mitochondrial function. Further analysis reveals that this protective effect is mediated through the BK receptor 2 (B2R) and its downstream PI3K/AKT pathway. Additionally, BK/PLGA sustained-release microspheres were developed and validated in a rat model, highlighting their potential therapeutic efficacy for IVDD. Overall, this study sheds light on the crucial role of the KKS in IVDD pathogenesis and suggests targeting the B2R as a promising therapeutic strategy to delay IVDD progression and promote disc regeneration.

In-Depth Serum Proteomics Reveals the Trajectory of Hallmarks of Cancer in Hepatitis B Virus-Related Liver Diseases

Hepatocellular carcinoma (HCC) is a prevalent cancer in China, with chronic hepatitis B (CHB) and liver cirrhosis (LC) being high-risk factors for developing HCC. Here, we determined the serum proteomes (762 proteins) of 125 healthy controls and Hepatitis B virus-infected CHB, LC, and HCC patients and constructed the first cancerous trajectory of liver diseases. The results not only reveal that the majority of altered biological processes were involved in the hallmarks of cancer (inflammation, metastasis, metabolism, vasculature, and coagulation) but also identify potential therapeutic targets in cancerous pathways (i.e., IL17 signaling pathway). Notably, the biomarker panels for detecting HCC in CHB and LC high-risk populations were further developed using machine learning in two cohorts comprised of 200 samples (discovery cohort = 125 and validation cohort = 75). The protein signatures significantly improved the area under the receiver operating characteristic curve of HCC (CHB discovery and validation cohort = 0.953 and 0.891, respectively; LC discovery and validation cohort = 0.966 and 0.818, respectively) compared to using the traditional biomarker, alpha-fetoprotein, alone. Finally, selected biomarkers were validated with parallel reaction monitoring mass spectrometry in an additional cohort (n = 120). Altogether, our results provide fundamental insights into the continuous changes of cancer biology processes in liver diseases and identify candidate protein targets for early detection and intervention.

The Role of Bradykinin Receptors in the Etiopathogenesis of Chronic Spontaneous Urticaria

Background and Objectives: Chronic spontaneous urticaria (CSU) is a distressing skin condition, which manifests as red, swollen, itchy, and sometimes painful hives or wheals appearing on skin. Recently, CSU has been associated with bradykinin release, which was previously discovered to be the main trigger of hereditary angioedema attacks. To study the role of bradykinin receptors 1 (BR1) and 2 (BR2) in the etiopathogenesis of CSU. Materials and Methods: A total of 60 individuals, 30 patients with CSU and 30 healthy subjects, were recruited to the study. CSU was diagnosed in accordance with the standardized protocol of dermatological assessment of skin symptoms. The level of bradykinin receptors was determined in populations of CD3⁺, CD4⁺, and CD8⁺ lymphocytes as well as in CD14⁺⁺CD16⁻, CD14⁺⁺CD16⁺ and CD14⁺CD16⁺ monocytes. In addition, urticaria activity score summed over 7 days (UAS-7) was assessed and correlated with BR1 and BR2 expression. Results: A statistically significant higher concentration of BR1 expression in lymphocytes was found in patients with CSU, compared to the control group (p < 0.001). Moreover, a statistically significant positive correlation was observed between UAS-7 and BR1/BR2 expression in CD14⁺⁺CD16⁻ cells (p = 0.03, R = 0.4). Conclusions: Bradykinin receptors are elevated in selected populations of lymphocytes in symptomatic CSU patients compared to healthy controls, indicating their role in the etiopathogenesis of the disease.

Repurposing existing drugs for the treatment of COVID-19/SARS-CoV-2 infection: A review describing drug mechanisms of action

The outbreak of a novel coronavirus (SARS-CoV-2) has caused a major public health concern across the globe. SARS-CoV-2 is the seventh coronavirus that is known to cause human disease. As of September 2020, SARS-CoV-2 has been reported in 213 countries and more than 31 million cases have been confirmed, with an estimated mortality rate of ∼3%. Unfortunately, a drug or vaccine is yet to be discovered to treat COVID-19. Thus, repurposing of existing cancer drugs will be a novel approach in treating COVID-19 patients. These drugs target viral replication cycle, viral entry and translocation to the nucleus. Some can enhance innate antiviral immune response as well. Hence this review focuses on comprehensive list of 22 drugs that work against COVID-19 infection. These drugs include fingolimod, colchicine, N4-hydroxycytidine, remdesivir, methylprednisone, oseltamivir, icatibant, perphanizine, viracept, emetine, homoharringtonine, aloxistatin, ribavirin, valrubicin, famotidine, almitrine, amprenavir, hesperidin, biorobin, cromolyn sodium, and antibodies- tocilzumab and sarilumab. Also, we provide a list of 31 drugs that are predicted to function against SARS-CoV-2 infection. In summary, we provide succinct overview of various therapeutic modalities. Among these 53 drugs, based on various clinical trials and literature, remdesivir, nelfinavir, methylpredinosolone, colchicine, famotidine and emetine may be used for COVID-19. SIGNIFICANCE: It is of utmost important priority to develop novel therapies for COVID-19. Since the effect of SARS-CoV-2 is so severe, slowing the spread of diseases will help the health care system, especially the number of visits to Intensive Care Unit (ICU) of any country. Several clinical trials are in works around the globe. Moreover, NCI developed a recent and robust response to COVID-19 pandemic. One of the NCI's goals is to screen cancer related drugs for identification of new therapies for COVID-19. https://www.cancer.gov/news-events/cancer-currents-blog/2020/covid-19-cancer-nci-response?cid=eb_govdel.

Kinin-B2 Receptor Activity in Skeletal Muscle Regeneration and Myoblast Differentiation

The bioactive peptide bradykinin obtained from cleavage of precursor kininogens activates the kinin-B2 receptor functioning in induction of inflammation and vasodilatation. In addition, bradykinin participates in kidney and cardiovascular development and neuronal and muscle differentiation. Here we show that kinin-B2 receptors are expressed throughout differentiation of murine C2C12 myoblasts into myotubes. An autocrine loop between receptor activation and bradykinin secretion is suggested, since bradykinin secretion is significantly reduced in the presence of the kinin-B2 receptor antagonist HOE-140 during differentiation. Expression of skeletal muscle markers and regenerative capacity were decreased after pharmacological inhibition or genetic ablation of the B2 receptor, while its antagonism increased the number of myoblasts in culture. In summary, the present work reveals to date no functions described for the B2 receptor in muscle regeneration due to the control of proliferation and differentiation of muscle precursor cells.

Involvement of the Bradykinin B1 Receptor in Microglial Activation: In Vitro and In Vivo Studies

The importance of brain inflammation to Alzheimer's disease (AD) pathogenesis has been accepted of late, with it currently being held that brain inflammation aggravates AD pathology. One important aspect of brain inflammation is the recruitment and activation of microglia, a process termed microgliosis. Kinins and bradykinin (BK), in particular, are major pro-inflammatory mediators in the periphery, although all of the factors comprising the kinin system have also been described in the brain. Moreover, it was shown that the amyloid β (Aβ) peptide (a component of AD plaques) enhances kinin secretion and activates BK receptors that can, in turn, stimulate Aβ production. Still, the role of bradykinin in modulating brain inflammation and AD is not completely understood. In this study, we aimed to investigate the roles of the bradykinin B₁ receptor (B₁R) and bradykinin B₂ receptor (B₂R) in regulating microglial secretion of pro-inflammatory factors in vitro. Furthermore, the effects of intranasal administration of specific B₁R and B₂R antagonists on Aβ burden and microglial accumulation in the brains of transgenic AD mice were studied. The data obtained show that neither R-715 (a B₁R antagonist) nor HOE 140 (a B₂R antagonist) altered microglial cell viability. However, R-715, but not HOE 140, markedly increased lipopolysaccharide-induced nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) release, as well as inducible nitric oxide synthase expression in BV2 microglial cells. Neither antagonist altered NO nor TNF-α production in non-stimulated cells. We also showed that intranasal administration of R-715 but not HOE 140 to 8-week-old 5X familial AD mice enhanced amyloid burden and microglia/macrophage accumulation in the cortex. To conclude, we provide evidence supporting a role of B₁R in brain inflammation and in the regulation of amyloid deposition in AD mice, possibly with microglial/macrophage involvement. Further studies are required to test whether modulation of this receptor can serve as a novel therapeutic strategy for AD.

Emerging concepts in the diagnosis and treatment of patients with undifferentiated angioedema

Angioedema is a sudden, transient swelling of well-demarcated areas of the dermis, subcutaneous tissue, mucosa, and submucosal tissues that can occur with or without urticaria. Up to 25% of people in the US will experience an episode of urticaria or angioedema during their lifetime, and many will present to the emergency department with an acute attack. Most cases of angioedema are attributable to the vasoactive mediators histamine and bradykinin. Histamine-mediated (allergic) angioedema occurs through a type I hypersensitivity reaction, whereas bradykinin-mediated (non-allergic) angioedema is iatrogenic or hereditary in origin.Although their clinical presentations bear similarities, the treatment algorithm for histamine-mediated angioedema differs significantly from that for bradykinin-mediated angioedema. Corticosteroids, and epinephrine are effective in the management of histamine-mediated angioedema but are ineffective in the management of bradykinin-mediated angioedema. Recent advancements in the understanding of angioedema have yielded pharmacologic treatment options for hereditary angioedema, a rare hereditary form of bradykinin-mediated angioedema. These novel therapies include a kallikrein inhibitor (ecallantide) and a bradykinin β2 receptor antagonist (icatibant). The physician's ability to distinguish between these types of angioedema is critical in optimizing outcomes in the acute care setting with appropriate treatment. This article reviews the pathophysiologic mechanisms, clinical presentations, and diagnostic laboratory evaluation of angioedema, along with acute management strategies for attacks.

Interaction between bradykinin and natriuretic peptides via RGS protein activation in HEK-293 cells

In this study, the interaction of natriuretic peptides (NP) and bradykinin (BK) signaling pathways was identified by measuring membrane potential (V(m)) and intracellular Ca(2+) using the patch-clamp technique and flow cytometry in HEK-293 cells. BK and NP receptor mRNA was identified using RT-PCR. BK (100 nM) depolarized cells activating bradykinin receptor type 2 (B(2)R) and Ca(2+)-dependent Cl(-) channels inhibitable by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB; 10 μM). The BK-induced Ca(2+) signal was blocked by the B(2)R inhibitor HOE 140. [Des-Arg(9)]-bradykinin, an activator of B(1)R, had no effect on intracellular Ca(2+). NP [atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and urodilatin] depolarized HEK-293 cells inhibiting K(+) channels. ANP, urodilatin, BNP [binding to natriuretic peptide receptor (NPR)-A] and 8-bromo-(8-Br)-cGMP inhibited the BK-induced depolarization while CNP (binding to NPR-Bi) failed to do so. The inhibitory effect on BK-triggered depolarization could be reversed by blocking PKG using the specific inhibitor KT 5823. BK-stimulated depolarization as well as Ca(2+) signaling was completely blocked by the phospholipase C (PLC) inhibitor U-73122 (10 nM). The inositol 1,4,5-trisphosphate receptor blocker 2-aminoethoxydiphenyl borate (2-APB; 50 μM) completely inhibited the BK-induced Ca(2+) signaling. UTP, another activator of the PLC-mediated Ca(2+) signaling pathway, was blocked by U-73122 as well but not by 8-Br-cGMP, indicating an intermediate regulatory step for NP via PKG in BK signaling such as regulators of G-protein signaling (RGS) proteins. When RGS proteins were inhibited by CCG-63802 in the presence of BK and 8-Br-cGMP, cells started to depolarize again. In conclusion, as natural antagonists of the B(2)R signaling pathway, NP may also positively interact in pathological conditions caused by BK.

The role of bradykinin and the effect of the bradykinin receptor antagonist icatibant in porcine sepsis

Bradykinin (BK) is regarded as an important mediator of edema, shock, and inflammation during sepsis. In this study, we evaluated the contribution of BK in porcine sepsis by blocking BK and by measuring the stable BK metabolite, BK1-5, using anesthetized pigs. The effect of BK alone, the efficacy of icatibant to block this effect, and the recovery of BK measured as plasma BK1-5 were first investigated. Purified BK injected intravenously induced an abrupt fall in blood pressure, which was completely prevented by pretreatment with icatibant. BK1-5 was detected in plasma corresponding to the doses given. The effect of icatibant was then investigated in an established model of porcine gram-negative sepsis. Neisseria meningitidis was infused intravenously without any pretreatment (n = 8) or pretreated with icatibant (n = 8). Negative controls received saline only. Icatibant-treated pigs developed the same degree of severe sepsis as did the controls. Both groups had massive capillary leakage, leukopenia, and excessive cytokine release. The plasma level of BK1-5 was low or nondetectable in all pigs. The latter observation was confirmed in supplementary studies with pigs undergoing Escherichia coli or polymicrobial sepsis induced by cecal ligation and puncture. In conclusion, icatibant completely blocked the hemodynamic effects of BK but had no beneficial effects on N. meningitidis-induced edema, shock, and inflammation. This and the fact that plasma BK1-5 in all the septic pigs was virtually nondetectable question the role of BK as an important mediator of porcine sepsis. Thus, the data challenge the current view of the role of BK also in human sepsis.

Kinin-B2 receptor mediated neuroprotection after NMDA excitotoxicity is reversed in the presence of kinin-B1 receptor agonists

Background

Kinins, with bradykinin and des-Arg⁹-bradykinin being the most important ones, are pro-inflammatory peptides released after tissue injury including stroke. Although the actions of bradykinin are in general well characterized; it remains controversial whether the effects of bradykinin are beneficial or not. Kinin-B2 receptor activation participates in various physiological processes including hypotension, neurotransmission and neuronal differentiation. The bradykinin metabolite des-Arg⁹-bradykinin as well as Lys-des-Arg⁹-bradykinin activates the kinin-B1 receptor known to be expressed under inflammatory conditions. We have investigated the effects of kinin-B1 and B2 receptor activation on N-methyl-D-aspartate (NMDA)-induced excitotoxicity measured as decreased capacity to produce synaptically evoked population spikes in the CA1 area of rat hippocampal slices.

Principal Findings

Bradykinin at 10 nM and 1 µM concentrations triggered a neuroprotective cascade via kinin-B2 receptor activation which conferred protection against NMDA-induced excitotoxicity. Recovery of population spikes induced by 10 nM bradykinin was completely abolished when the peptide was co-applied with the selective kinin-B2 receptor antagonist HOE-140. Kinin-B2 receptor activation promoted survival of hippocampal neurons via phosphatidylinositol 3-kinase, while MEK/MAPK signaling was not involved in protection against NMDA-evoked excitotoxic effects. However, 100 nM Lys-des-Arg⁹-bradykinin, a potent kinin-B1 receptor agonist, reversed bradykinin-induced population spike recovery. The inhibition of population spikes recovery was reversed by PD98059, showing that MEK/MAPK was involved in the induction of apoptosis mediated by the B1 receptor.

Conclusions

Bradykinin exerted protection against NMDA-induced excitotoxicity which is reversed in the presence of a kinin-B1 receptor agonist. As bradykinin is converted to the kinin-B1 receptor metabolite des-Arg⁹-bradykinin by carboxypeptidases, present in different areas including in brain, our results provide a mechanism for the neuroprotective effect in vitro despite of the deleterious effect observed in vivo.

Evidence-based recommendations for the therapeutic management of angioedema owing to hereditary C1 inhibitor deficiency: consensus report of an International Working Group

Angioedema owing to hereditary deficiency of C1 inhibitor (HAE) is a rare, life-threatening, disabling disease. In the last 2 years, the results of well-designed and controlled trials with existing and new therapies for this condition have been published, and new treatments reached the market. Current guidelines for the treatment for HAE were released before the new trials and before the new treatments became available and were essentially based on observational studies and expert opinion. To provide evidence-based HAE treatment guidelines supported by the new studies, a conference was held in Gargnano del Garda, Italy, from September 26 to 29, 2010. The meeting hosted 58 experienced HAE expert physicians, representatives of pharmaceutical companies and representatives of HAE patients' associations. Here, we report the topics discussed during the meeting and evidence-based consensus about management approaches for HAE in adult/adolescent patients.

Icatibant in hereditary angioedema: news and challenges

Hereditary angioedema (HAE) is a rare condition. Its prognosis depends on whether there is laryngeal involvement with a risk of asphyxia, which is present in 25% of such cases. Improved understanding of the pathophysiology of this disease has resulted in the development of targeted therapies including icatibant, which acts as an antagonist at bradykinin B2 receptors. This agent has been shown to be effective in the treatment of attacks of HAE in three Phase III randomized double-blind published studies. Efficacy data have been collected in all types of attack: cutaneous, abdominal and laryngeal. Safety data are also encouraging. Icatibant is administered subcutaneously, with the potential for patients to self-administer. In the future, this therapy may offer increased independence for HAE patients.

Cardioprotective effects of tanshinone IIA pretreatment via kinin B2 receptor-Akt-GSK-3β dependent pathway in experimental diabetic cardiomyopathy

Aims

Diabetic cardiomyopathy, characterized by myocardial structural and functional changes, is a specific cardiomyopathy develops in patients with diabetes mellitus. The present study was to investigate the role of kinin B2 receptor-Akt-glycogen synthase kinase (GSK)-3β signalling pathway in mediating the protective effects of tanshinone IIA (TSN) on diabetic cardiomyopathy.

Methods and results

Streptozocin (STZ) induced diabetic rats (n = 60) were randomized to receive TSN, TSN plus HOE140 (a kinin B2 receptor antagonist), or saline. Healthy Sprague-Dawley (SD) rats (n = 20) were used as control. Left ventricular function, myocardial apoptosis, myocardial ultrastructure, Akt, GSK-3β and NF-κB phosphorylation, the expression of TNF-α, IL-6 and myeloperoxidase (MPO) were examined. Cardiac function was well preserved as evidenced by increased left ventricular ejection fraction (LVEF) and ± dp/dt (maximum speed of contraction/relaxation), along with decreased myocardial apoptotic death after TSN administration. TSN pretreatment alleviated mitochondria ultrastructure changes. TSN also enhanced Akt and GSK-3β phosphorylation and inhibited NF-κB phosphorylation, resulting in decreased TNF-α, IL-6 and MPO activities. Moreover, pretreatment with HOE140 abolished the beneficial effects of TSN: a decrease in LVEF and ± dp/dt, an inhibition of cardiomyocyte apoptosis, a destruction of cardiomyocyte mitochondria cristae, a reduction of Akt and GSK-3β phosphorylation, an enhancement of NF-κB phosphorylation and an increase of TNF-α, IL-6 and MPO production.

Conclusion

These data indicated that TSN is cardioprotective in the context of diabetic cardiomyopathy through kinin B2 receptor-Akt-GSK-3β dependent pathway.

Management of acute attacks of hereditary angioedema: potential role of icatibant

Icatibant (Firazyr(®)) is a novel subcutaneous treatment recently licensed in the European Union for acute hereditary angioedema. Hereditary angioedema, resulting from inherited partial C1 inhibitor deficiency, is a disabling condition characterized by intermittent episodes of bradykinin-mediated angioedema. Icatibant blocks bradykinin B2 receptors, attenutating the episode. Randomized double-blind, placebo-controlled trials of icatibant, showed significant superiority over oral tranexamic acid in 74 European patients and a trend to improvement in a similar US trial comparing icatibant with placebo in 55 patients. Outcomes for several endpoints did not reach significance in the US trial, perhaps because of low participant numbers and confounding factors: a further trial is planned. Open label studies have shown benefit in multiple treatments for attacks at all sites. Approximately 10% of patients require a second dose for re-emergent symptoms, usually 10 to 27 hours after the initial treatment. Its subcutaneous route of administration, good tolerability and novel mode of action make icatibant a promising addition to the limited repertoire of treatments for hereditary angioedema.

HAE therapies: past present and future

Advances in understanding the pathophysiology and mechanism of swelling in hereditary angioedema (HAE) has resulted in the development of multiple new drugs for the acute and prophylactic treatment of patients with HAE. This review will recap the past treatment options, review the new current treatment options, and discuss potential future treatment options for patients with HAE.

Peri-operative management of a patient with hereditary angioedema undergoing laparoscopic cholecystectomy

Hereditary angioedema is a rare genetic disorder resulting from an inherited deficiency or dysfunction of the C1-esterase inhibitor of the classic complement pathway. It is characterised by recurrent episodes of angioedema, without urticaria or pruritus, most often affecting the skin or the mucosal tissues of the upper respiratory and gastrointestinal tracts. We describe the peri-operative care of a woman with hereditary angioedema undergoing laparoscopic cholecystectomy with emphasis on the role of anaesthetists as peri-operative physicians.

Pharmacological characterization of the bradykinin B2 receptor antagonist MEN16132 in rat in vitro bioassays

The pharmacological profile of the bradykinin B(2) receptor antagonist MEN16132 at the rat B(2) receptor has been investigated and compared with that of icatibant (formerly Hoe 140). Antagonist affinity has been measured through radioligand binding experiments with membranes prepared from uterine and airway tissue. MEN16132 inhibited [(3)H]bradykinin binding with subnanomolar affinity (pK(i) values 10.4 and 10.1 in the uterus and airways, respectively), and was about 3-fold less potent than icatibant (pK(i) values 10.9 and 10.5). Antagonist potency has been estimated towards bradykinin-induced contractility of uterine and urinary bladder smooth muscle preparations. In these assays MEN16132 (pK(B): 9.7 both in uterus and bladder) was about 10-fold more potent than icatibant [pK(B): 8.8 in uterus, and pK(B) 8.0 in urinary bladder, as from Meini, S., Patacchini, R., Giuliani, S., Lazzeri, M., Turini, D., Maggi, C.A., Lecci, A., 2000a. Characterization of bradykinin B(2) receptor antagonists in human and rat urinary bladder. Eur. J. Pharmacol. 388, 177-182]. Washout experiments conducted in the uterine preparation indicated for MEN16132 (100 nM) a slower reversibility than icatibant (300 nM).Altogether present results indicate that MEN16132 displays high affinity and potency also for the rat bradykinin B(2) receptor, and thus is suitable for further investigations in pathophysiological models in this species.