-
Blood Mar 2020In this issue of , Noubouossie et al provide new insights into potential mechanisms for thromboinflammatory complications associated with red blood cell (RBC)...
In this issue of , Noubouossie et al provide new insights into potential mechanisms for thromboinflammatory complications associated with red blood cell (RBC) transfusions. By using leukoreduced RBC units to isolate RBC microvesicles (RBC-MVs), they document that RBC-MVs activate factor IX (FIX) via 2 distinct pathways: (1) the canonical intrinsic pathway in which activated FXII (FXIIa) activates FIX in an FXI-dependent manner and (2) a noncanonical pathway in which plasma kallikrein directly activates FIX, which ultimately results in thrombin generation.
Topics: Blood Coagulation Tests; Cell-Derived Microparticles; Erythrocytes; Factor IX
PubMed: 32135018
DOI: 10.1182/blood.2020004985 -
Diabetes May 2011Plasma kallikrein (PK) has been identified in vitreous fluid obtained from individuals with diabetic retinopathy and has been implicated in contributing to retinal...
OBJECTIVE
Plasma kallikrein (PK) has been identified in vitreous fluid obtained from individuals with diabetic retinopathy and has been implicated in contributing to retinal vascular dysfunction. In this report, we examined the effects of PK on retinal vascular functions and thickness in diabetic rats.
RESEARCH DESIGN AND METHODS
We investigated the effects of a selective PK inhibitor, ASP-440, and C1 inhibitor (C1-INH), the primary physiological inhibitor of PK, on retinal vascular permeability (RVP) and hemodynamics in rats with streptozotocin-induced diabetes. The effect of intravitreal PK injection on retinal thickness was examined by spectral domain optical coherence tomography.
RESULTS
Systemic continuous administration of ASP-440 for 4 weeks initiated at the time of diabetes onset inhibited RVP by 42% (P = 0.013) and 83% (P < 0.001) at doses of 0.25 and 0.6 mg/kg per day, respectively. Administration of ASP-440 initiated 2 weeks after the onset of diabetes ameliorated both RVP and retinal blood flow abnormalities in diabetic rats measured at 4 weeks' diabetes duration. Intravitreal injection of C1-INH similarly decreased impaired RVP in rats with 2 weeks' diabetes duration. Intravitreal injection of PK increased both acute RVP and sustained focal RVP (24 h postinjection) to a greater extent in diabetic rats compared with nondiabetic control rats. Intravitreal injection of PK increased retinal thickness compared with baseline to a greater extent (P = 0.017) in diabetic rats (from 193 ± 10 μm to 223 ± 13 μm) compared with nondiabetic rats (from 182 ± 8 μm to 193 ± 9 μm).
CONCLUSIONS
These results show that PK contributes to retinal vascular dysfunctions in diabetic rats and that the combination of diabetes and intravitreal injection of PK in rats induces retinal thickening.
Topics: Animals; Complement C1 Inhibitor Protein; Enzyme Inhibitors; Fluorescein Angiography; Fluorophotometry; Hemodynamics; Humans; Male; Plasma Kallikrein; Rats; Rats, Sprague-Dawley; Retina
PubMed: 21444925
DOI: 10.2337/db10-1260 -
Proceedings of the National Academy of... Jan 2021Kallikrein (PKa), generated by activation of its precursor prekallikrein (PK), plays a role in the contact activation phase of coagulation and functions in the...
Kallikrein (PKa), generated by activation of its precursor prekallikrein (PK), plays a role in the contact activation phase of coagulation and functions in the kallikrein-kinin system to generate bradykinin. The general dogma has been that the contribution of PKa to the coagulation cascade is dependent on its action on FXII. Recently this dogma has been challenged by studies in human plasma showing thrombin generation due to PKa activity on FIX and also by murine studies showing formation of FIXa-antithrombin complexes in FXI deficient mice. In this study, we demonstrate high-affinity binding interactions between PK(a) and FIX(a) using surface plasmon resonance and show that these interactions are likely to occur under physiological conditions. Furthermore, we directly demonstrate dose- and time-dependent cleavage of FIX by PKa in a purified system by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and chromogenic assays. By using normal pooled plasma and a range of coagulation factor-deficient plasmas, we show that this action of PKa on FIX not only results in thrombin generation, but also promotes fibrin formation in the absence of FXII or FXI. Comparison of the kinetics of either FXIa- or PKa-induced activation of FIX suggest that PKa could be a significant physiological activator of FIX. Our data indicate that the coagulation cascade needs to be redefined to indicate that PKa can directly activate FIX. The circumstances that drive PKa substrate specificity remain to be determined.
Topics: Blood Coagulation; Bradykinin; Calcium; Cations, Divalent; Factor IX; Factor XI; Factor XII; Fibrin; Humans; Kallikreins; Kinetics; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylserines; Protein Binding; Thrombin
PubMed: 33397811
DOI: 10.1073/pnas.2014810118 -
Clinical and Translational Science Apr 2022Hereditary angioedema (HAE) is an autosomal dominant disorder characterized by recurrent episodes of swelling of the skin, larynx, gastrointestinal tract, genitals, and...
Hereditary angioedema (HAE) is an autosomal dominant disorder characterized by recurrent episodes of swelling of the skin, larynx, gastrointestinal tract, genitals, and extremities that can be disruptive to patient quality of life. Dysregulation of plasma kallikrein activity leads to increased production and accumulation of bradykinin in HAE and causes attacks of angioedema. Plasma kallikrein is a serine protease essential for the formation of bradykinin. Berotralstat is a potent, highly selective, orally bioavailable small-molecule plasma kallikrein inhibitor that has been approved to prevent attacks of HAE in adults and children 12 years of age and older. Population pharmacokinetic (PK) analyses were conducted to describe the PK of berotralstat (BCX7353; Orladeyo ) and to evaluate the covariates that may explain variability in PK. The PK of berotralstat were characterized by population PK modeling of data from 13 clinical studies and a total of 771 healthy subjects and patients with HAE. The PK profile was well described by a three-compartment model with first-order absorption including an absorption lag time and linear elimination. Among the covariates tested, the effects of bilirubin and food were found not to be clinically significant and were removed from the model. Covariate analysis indicated significant effects of dose on bioavailability and weight on berotralstat clearance and volume. Despite the covariate effect of weight, simulations in adolescents and adults who were underweight, low weight, and overweight demonstrated similar predicted exposures to those observed at therapeutic doses in a clinical trial. Therefore, no dose adjustment is required in these HAE patient subpopulations.
Topics: Adolescent; Adult; Angioedemas, Hereditary; Bradykinin; Child; Humans; Plasma Kallikrein; Pyrazoles; Quality of Life
PubMed: 35212456
DOI: 10.1111/cts.13233 -
Journal of Medicinal Chemistry Oct 2022Hereditary angioedema (HAE) is a rare genetic disorder in which patients experience sudden onset of swelling in various locations of the body. HAE is associated with...
Sebetralstat (KVD900): A Potent and Selective Small Molecule Plasma Kallikrein Inhibitor Featuring a Novel P1 Group as a Potential Oral On-Demand Treatment for Hereditary Angioedema.
Hereditary angioedema (HAE) is a rare genetic disorder in which patients experience sudden onset of swelling in various locations of the body. HAE is associated with uncontrolled plasma kallikrein (PKa) enzyme activity and generation of the potent inflammatory mediator, bradykinin, resulting in episodic attacks of angioedema. Herein, we disclose the discovery and optimization of novel small molecule PKa inhibitors. Starting from molecules containing highly basic P1 groups, which typically bind to an aspartic acid residue (Asp189) in the serine protease S1 pocket, we identified novel P1 binding groups likely to have greater potential for oral-drug-like properties. The optimization of P4 and the central core together with the particularly favorable properties of 3-fluoro-4-methoxypyridine P1 led to the development of sebetralstat, a potent, selective, orally bioavailable PKa inhibitor in phase 3 for on-demand treatment of HAE attacks.
Topics: Humans; Administration, Oral; Angioedemas, Hereditary; Antiviral Agents; Aspartic Acid; Bradykinin; Plasma Kallikrein
PubMed: 36251573
DOI: 10.1021/acs.jmedchem.2c00921 -
Cardiovascular Diabetology Sep 2022Post-acute sequelae of COVID-19 (PASC), also now known as long COVID, has become a major global health and economic burden. Previously, we provided evidence that there...
Proteomics of fibrin amyloid microclots in long COVID/post-acute sequelae of COVID-19 (PASC) shows many entrapped pro-inflammatory molecules that may also contribute to a failed fibrinolytic system.
BACKGROUND
Post-acute sequelae of COVID-19 (PASC), also now known as long COVID, has become a major global health and economic burden. Previously, we provided evidence that there is a significant insoluble fibrin amyloid microclot load in the circulation of individuals with long COVID, and that these microclots entrap a substantial number of inflammatory molecules, including those that might prevent clot breakdown. Scientifically, the most challenging aspect of this debilitating condition is that traditional pathology tests such as a serum CRP (C-reactive protein) may not show any significant abnormal inflammatory markers, albeit these tests measure only the soluble inflammatory molecules. Elevated, or abnormal soluble biomarkers such as IL-6, D-Dimer or fibrinogen indicate an increased risk for thrombosis or a host immune response in COVID-19. The absence of biomarkers in standard pathology tests, result in a significant amount of confusion for patients and clinicians, as patients are extremely sick or even bed-ridden but with no regular identifiable reason for their disease. Biomarkers that are currently available cannot detect the molecules present in the microclots we identified and are therefore unable to confirm their presence or the mechanisms that drive their formation.
METHODS
Here we analysed the protein content of double-digested microclots of 99 long COVID patients and 29 healthy controls. The patients suffering from long COVID reported their symptoms through a questionnaire completed by themselves or their attending physician.
RESULTS
Our long COVID cohort's symptoms were found to be in line with global findings, where the most prevalent symptoms were constant fatigue (74%,) cognitive impairment (71%) and depression and anxiety (30%). Our most noteworthy findings were a reduced level of plasma Kallikrein compared to our controls, an increased level of platelet factor 4 (PF4) von Willebrand factor (VWF), and a marginally increased level of α-2 antiplasmin (α-2-AP). We also found a significant presence of antibodies entrapped inside these microclots.
CONCLUSION
Our results confirm the presence of pro-inflammatory molecules that may also contribute to a failed fibrinolysis phenomenon, which could possibly explain why individuals with long COVID suffer from chronic fatigue, dyspnoea, or cognitive impairment. In addition, significant platelet hyperactivation was noted. Hyperactivation will result in the granular content of platelets being shed into the circulation, including PF4. Overall, our results provide further evidence of both a failed fibrinolytic system in long COVID/PASC and the entrapment of many proteins whose presence might otherwise go unrecorded. These findings might have significant implications for individuals with pre-existing comorbidities, including cardiovascular disease and type 2 diabetes.
Topics: Biomarkers; C-Reactive Protein; COVID-19; Diabetes Mellitus, Type 2; Fibrin; Fibrinogen; Humans; Interleukin-6; Plasma Kallikrein; Platelet Factor 4; Proteomics; Thrombosis; alpha-2-Antiplasmin; von Willebrand Factor; Post-Acute COVID-19 Syndrome
PubMed: 36131342
DOI: 10.1186/s12933-022-01623-4 -
Clinical Drug Investigation Jul 2015Hereditary angioedema (HAE), a rare autosomal dominant genetic disorder, is caused by a deficiency in functional C1 esterase inhibitor (C1-INH). This potentially... (Review)
Review
Hereditary angioedema (HAE), a rare autosomal dominant genetic disorder, is caused by a deficiency in functional C1 esterase inhibitor (C1-INH). This potentially life-threatening condition manifests as recurrent attacks of subcutaneous and submucosal swelling of the skin, gastrointestinal tract and larynx. The management of HAE includes treatment of acute episodes, short-term prophylaxis in preparation for exposure to known triggers and long-term prophylaxis to decrease the incidence and severity of HAE attacks. Four products are approved in the USA for the treatment of acute attacks of HAE, including one human plasma-derived C1-INH therapy, a recombinant human C1-INH product (rhC1-INH), a plasma kallikrein inhibitor and a bradykinin B2 receptor antagonist. In addition, one human plasma-derived C1-INH therapy and danazol are approved for prophylaxis of HAE attacks. rhC1-INH, extracted from the milk of transgenic rabbits, is a glycoprotein of 478 amino acids with an identical amino acid sequence to the endogenous human C1-INH protein. Population pharmacokinetic analysis of rhC1-INH supports an intravenous dosing strategy of 50 U/kg (maximum 4200 U). The safety and efficacy of rhC1-INH in the treatment of acute attacks in patients with HAE were demonstrated in three randomized, double-blind, placebo-controlled studies and two open-label extension studies. In a pilot prophylaxis study, weekly administration of rhC1-INH 50 U/kg for 8 weeks reduced the incidence of HAE attacks and was well tolerated. Administration of rhC1-INH has not been associated with the development of anti-drug antibodies or antibodies to anti-host-related impurities.
Topics: Angioedemas, Hereditary; Complement C1 Inhibitor Protein; Humans; Immunoglobulin E; Randomized Controlled Trials as Topic; Recombinant Proteins
PubMed: 26091744
DOI: 10.1007/s40261-015-0300-z -
Blood May 2022Patients with hereditary angioedema (HAE) experience episodes of bradykinin (BK)-induced swelling of skin and mucosal membranes. The most common cause is reduced plasma...
Patients with hereditary angioedema (HAE) experience episodes of bradykinin (BK)-induced swelling of skin and mucosal membranes. The most common cause is reduced plasma activity of C1 inhibitor, the main regulator of the proteases plasma kallikrein (PKa) and factor XIIa (FXIIa). Recently, patients with HAE were described with a Lys311 to glutamic acid substitution in plasminogen (Plg), the zymogen of the protease plasmin (Plm). Adding tissue plasminogen activator to plasma containing Plg-Glu311 vs plasma containing wild-type Plg (Plg-Lys311) results in greater BK generation. Similar results were obtained in plasma lacking prekallikrein or FXII (the zymogens of PKa and FXIIa) and in normal plasma treated with a PKa inhibitor, indicating Plg-Glu311 induces BK generation independently of PKa and FXIIa. Plm-Glu311 cleaves high and low molecular weight kininogens (HK and LK, respectively), releasing BK more efficiently than Plm-Lys311. Based on the plasma concentrations of HK and LK, the latter may be the source of most of the BK generated by Plm-Glu311. The lysine analog ε-aminocaproic acid blocks Plm-catalyzed BK generation. The Glu311 substitution introduces a lysine-binding site into the Plg kringle 3 domain, perhaps altering binding to kininogens. Plg residue 311 is glutamic acid in most mammals. Glu311 in patients with HAE, therefore, represents reversion to the ancestral condition. Substantial BK generation occurs during Plm-Glu311 cleavage of human HK, but not mouse HK. Furthermore, mouse Plm, which has Glu311, did not liberate BK from human kininogens more rapidly than human Plg-Lys311. This indicates Glu311 is pathogenic in the context of human Plm when human kininogens are the substrates.
Topics: Angioedemas, Hereditary; Animals; Bradykinin; Factor XIIa; Fibrinolysin; Glutamic Acid; Humans; Kininogens; Lysine; Mammals; Mice; Plasma Kallikrein; Plasminogen; Tissue Plasminogen Activator
PubMed: 35100351
DOI: 10.1182/blood.2021012945 -
Materials Today. Bio Dec 2022Protein adsorption to biomaterial surfaces is considered a determining factor for the host response. Here we detail the protein adsorption profiles of alginate hydrogel...
Protein adsorption to biomaterial surfaces is considered a determining factor for the host response. Here we detail the protein adsorption profiles of alginate hydrogel microspheres relevant for cell therapy using mass spectrometry (MS)-based proteomics. The investigated microspheres include sulfated alginate (SA), high G alginate (HiG), and poly-l-lysine coated alginate (AP), which previously have been shown to exhibit different inflammatory and fibrotic responses. The biological significance was assessed in lepirudin-anticoagulated human whole blood (hWB) by functional analysis of the acute-phase responses (complement and coagulation). Proteomic profiling revealed distinct signatures for the microspheres, wherein Ingenuity Pathway Analysis identified complement and coagulation as the top enriched canonical pathways. The levels of complement and coagulation activators and inhibitors were distinctly different, which was reflected in the functional hWB analyses: SA was highly enriched with inhibitory factors of complement and coagulation (e.g. C1 inhibitor, factor H, antithrombin-III, heparin cofactor 2), other heparin-binding proteins and factors promoting fibrinolysis (factor XII, plasma kallikrein), conforming to an anti-inflammatory and anti-fibrotic profile. HiG enriched moderate levels of complement inhibitors, conforming to a low-inflammatory and pro-fibrotic profile. AP showed the most prominent enrichment of complement activators (e.g. C3, properdin, C-reactive protein) and low levels of inhibitors, conforming to a pro-inflammatory and highly pro-fibrotic profile. In conclusion, the extensive enrichment of inhibitory acute-phase proteins on SA could be a determining factor for its reduced host response. The interactions between the plasma proteins and hydrogel surfaces shown herein point to proteomics as an important supplement to existing and methods for designing biocompatible alginate-based hydrogels.
PubMed: 36420052
DOI: 10.1016/j.mtbio.2022.100490 -
Medecine Sciences : M/S Dec 2019Monogenic diseases are rare genetic diseases but they are numerous and display a highly variable degree of severity. First uses of monoclonal antibodies to treat... (Review)
Review
Monogenic diseases are rare genetic diseases but they are numerous and display a highly variable degree of severity. First uses of monoclonal antibodies to treat monogenic diseases started in the 2000's and many clinical trials are ongoing. Anti-IL-1β therapies have greatly modified the outcome of auto-inflammatory diseases by modulating inflammatory response and reducing the risk of secondary amyloidosis. Anti-TNF-α are also used in such diseases. In atypical hemolytic and uremic syndrome due to deficiencies in the control of alternative complement pathway, eculizumab, an anti-C5 monoclonal antibody, has improved renal outcome in treated patients. More recently, lanadelumab, an anti-plasma kallikrein antibody, has reinforced the therapeutic arsenal in hereditary angioedema and burosumab, anti-FGF23, that of X-linked hypophosphatemia. Such examples reflect the importance of monoclonal antibody therapy of monogenic diseases, the interest of considering such an option as well as the need for future researches.
Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Fibroblast Growth Factor-23; Genetic Diseases, Inborn; Humans; Interleukin-1beta; Tumor Necrosis Factor-alpha
PubMed: 31903913
DOI: 10.1051/medsci/2019203