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British Journal of Anaesthesia May 2018Neutralisation of systemic anticoagulation with heparin in cardiac surgery with cardiopulmonary bypass requires protamine administration. If adequately dosed, protamine... (Review)
Review
Neutralisation of systemic anticoagulation with heparin in cardiac surgery with cardiopulmonary bypass requires protamine administration. If adequately dosed, protamine neutralises heparin and reduces the risk of postoperative bleeding. However, as its anticoagulant properties are particularly exerted in the absence of heparin, overdosing of protamine may contribute to bleeding and increased transfusion requirements. This narrative review describes the mechanisms underlying the anticoagulant properties and side-effects of protamine, and the impact of protamine dosing on the activated clotting time and point-of-care viscoelastic test results, and explains the distinct protamine dosing strategies in relation to haemostatic activation and postoperative bleeding. The available evidence suggests that protamine dosing should not exceed a protamine-to-heparin ratio of 1:1. In particular, protamine-to-heparin dosing ratios >1 are associated with more postoperative 12 h blood loss. The optimal protamine-to-heparin ratio in cardiac surgery has, however, not yet been elaborated, and may vary between 0.6 and 1.0 based on the initial heparin dose.
Topics: Anticoagulants; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Dose-Response Relationship, Drug; Heparin; Heparin Antagonists; Humans; Postoperative Hemorrhage; Protamines
PubMed: 29661409
DOI: 10.1016/j.bja.2018.01.023 -
Clinical and Applied... Jul 2017Bleeding is the most common complication of all anticoagulants. Any bleeding patient on an anticoagulant should be risk-stratified based on hemodynamic instability,... (Review)
Review
Bleeding is the most common complication of all anticoagulants. Any bleeding patient on an anticoagulant should be risk-stratified based on hemodynamic instability, source of bleeding, and degree of blood loss. Although minor bleed may be managed with discontinuation of anticoagulant, major bleed may require transfusion of blood products and use of specific antidote. The residual effects of each anticoagulant may be monitored with distinct coagulation assay. Intravenous or oral vitamin K can reverse the effect of warfarin within 24 to 48 hours and is indicated for any bleeding, international normalized ratio of >10 or 4.5 to 10 in patients with other risk factors for bleeding. Fresh frozen plasma or prothrombin complex concentrate (PCC) may be necessary in major bleeding related to warfarin. Protamine sulfate reverses the effect of unfractionated heparin completely and of low-molecular-weight heparin (LMWH) partially. Idarucizumab has recently been approved in United States for dabigatran reversal, whereas andexanet alfa is expected to get approved in the near future for reversal of oral factor Xa inhibitors. The PCC may reverse the effect of rivaroxaban to some extent, but no data are available regarding reversal of apixaban and edoxaban. Aripazine has shown promising results to reverse the effects of LMWH, fondaparinux, and direct oral anticoagulants but is still in the developmental phase.
Topics: Antibodies, Monoclonal, Humanized; Anticoagulants; Antidotes; Blood Coagulation Factors; Blood Coagulation Tests; Hemorrhage; Humans; International Normalized Ratio; Plasma; Protamines
PubMed: 27789605
DOI: 10.1177/1076029616675970 -
Journal of Thrombosis and Haemostasis :... Nov 2018Despite the development of catheter-based interventions for ischemic and valvular heart disease, hundreds of thousands of people undergo open heart surgery annually for... (Review)
Review
Despite the development of catheter-based interventions for ischemic and valvular heart disease, hundreds of thousands of people undergo open heart surgery annually for coronary artery bypass graft (CABG), valve replacement or cardiac assist device implantation. Cardiac surgery patients are unique because therapeutic anticoagulation is required during cardiopulmonary bypass. Developmental hemostasis and altered drug metabolism affect management in children. This narrative review summarizes the current evidence-based and consensus guidelines regarding perioperative, intraoperative and postoperative antithrombotic therapy in patients undergoing cardiac surgery. Anticoagulation preoperatively is required in the setting of cardiac arrhythmias, prior valve replacement or history of venous thromboembolism. In patients with ischemic heart disease, aspirin is continued in the perioperative period, whereas oral P2Y antagonists are withheld for 5-7 days to reduce the risk of perioperative bleeding. Intraoperative management of cardiopulmonary bypass in adults and children includes anticoagulation with unfractionated heparin. Variability in dose-response to heparin and influence of other medical conditions on dosing and reversal of heparin make intraoperative anticoagulation challenging. Vitamin K antagonist therapy is the standard anticoagulant after mechanical heart valve or left ventricular assist device (LVAD) implantation. Longer duration of dual antiplatelet therapy is recommended after CABG if patients undergo surgery because of acute coronary syndrome. Antiplatelet therapy after LVAD implantation includes aspirin, dipyridamole and/or clopidogrel in children and aspirin in adults. A coordinated approach between hematology, cardiology, anesthesiology, critical care and cardiothoracic surgery can assist to balance the risk of thrombosis and bleeding in patients undergoing cardiac surgery.
Topics: Adolescent; Adult; Anticoagulants; Aspirin; Blood Coagulation; Cardiac Surgical Procedures; Cardiology; Child; Coronary Artery Bypass; Drug Administration Schedule; Evidence-Based Medicine; Fibrinolytic Agents; Heart Valve Diseases; Heart-Assist Devices; Hemorrhage; Hemostasis; Heparin; Humans; Inflammation; Intraoperative Period; Perioperative Period; Platelet Aggregation Inhibitors; Practice Guidelines as Topic; Protamines; Risk; Thrombolytic Therapy; Thrombosis; Vitamin K
PubMed: 30153372
DOI: 10.1111/jth.14276 -
Cell Mar 2020The paternal genome undergoes a massive exchange of histone with protamine for compaction into sperm during spermiogenesis. Upon fertilization, this process is potently...
The paternal genome undergoes a massive exchange of histone with protamine for compaction into sperm during spermiogenesis. Upon fertilization, this process is potently reversed, which is essential for parental genome reprogramming and subsequent activation; however, it remains poorly understood how this fundamental process is initiated and regulated. Here, we report that the previously characterized splicing kinase SRPK1 initiates this life-beginning event by catalyzing site-specific phosphorylation of protamine, thereby triggering protamine-to-histone exchange in the fertilized oocyte. Interestingly, protamine undergoes a DNA-dependent phase transition to gel-like condensates and SRPK1-mediated phosphorylation likely helps open up such structures to enhance protamine dismissal by nucleoplasmin (NPM2) and enable the recruitment of HIRA for H3.3 deposition. Remarkably, genome-wide assay for transposase-accessible chromatin sequencing (ATAC-seq) analysis reveals that selective chromatin accessibility in both sperm and MII oocytes is largely erased in early pronuclei in a protamine phosphorylation-dependent manner, suggesting that SRPK1-catalyzed phosphorylation initiates a highly synchronized reorganization program in both parental genomes.
Topics: Animals; Cell Cycle Proteins; Cell Nucleus; Chromatin; Chromatin Assembly and Disassembly; Fertilization; Histones; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Oocytes; Phosphorylation; Protamine Kinase; Protamines; Protein Serine-Threonine Kinases; RNA Splicing; Spermatozoa; Transcription Factors; Zygote
PubMed: 32169215
DOI: 10.1016/j.cell.2020.02.020 -
Molecular Therapy : the Journal of the... Jun 2017Recently, the World Health Organization confirmed 120 new human cases of avian H7N9 influenza in China resulting in 37 deaths, highlighting the concern for a potential...
Recently, the World Health Organization confirmed 120 new human cases of avian H7N9 influenza in China resulting in 37 deaths, highlighting the concern for a potential pandemic and the need for an effective, safe, and high-speed vaccine production platform. Production speed and scale of mRNA-based vaccines make them ideally suited to impede potential pandemic threats. Here we show that lipid nanoparticle (LNP)-formulated, modified mRNA vaccines, encoding hemagglutinin (HA) proteins of H10N8 (A/Jiangxi-Donghu/346/2013) or H7N9 (A/Anhui/1/2013), generated rapid and robust immune responses in mice, ferrets, and nonhuman primates, as measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays. A single dose of H7N9 mRNA protected mice from a lethal challenge and reduced lung viral titers in ferrets. Interim results from a first-in-human, escalating-dose, phase 1 H10N8 study show very high seroconversion rates, demonstrating robust prophylactic immunity in humans. Adverse events (AEs) were mild or moderate with only a few severe and no serious events. These data show that LNP-formulated, modified mRNA vaccines can induce protective immunogenicity with acceptable tolerability profiles.
Topics: Animals; Antibodies, Viral; Cell Line; Disease Models, Animal; Female; Ferrets; Gene Expression; Humans; Immunization; Immunization Schedule; Influenza A Virus, H10N8 Subtype; Influenza A Virus, H7N9 Subtype; Influenza Vaccines; Macaca fascicularis; Male; Mice; Orthomyxoviridae Infections; Protamines; RNA, Messenger; RNA, Viral; Tissue Distribution
PubMed: 28457665
DOI: 10.1016/j.ymthe.2017.03.035 -
Cell Jun 2017Genetic studies have elucidated critical roles of Piwi proteins in germline development in animals, but whether Piwi is an actual disease gene in human infertility...
Genetic studies have elucidated critical roles of Piwi proteins in germline development in animals, but whether Piwi is an actual disease gene in human infertility remains unknown. We report germline mutations in human Piwi (Hiwi) in patients with azoospermia that prevent its ubiquitination and degradation. By modeling such mutations in Piwi (Miwi) knockin mice, we demonstrate that the genetic defects are directly responsible for male infertility. Mechanistically, we show that MIWI binds the histone ubiquitin ligase RNF8 in a Piwi-interacting RNA (piRNA)-independent manner, and MIWI stabilization sequesters RNF8 in the cytoplasm of late spermatids. The resulting aberrant sperm show histone retention, abnormal morphology, and severely compromised activity, which can be functionally rescued via blocking RNF8-MIWI interaction in spermatids with an RNF8-N peptide. Collectively, our findings identify Piwi as a factor in human infertility and reveal its role in regulating the histone-to-protamine exchange during spermiogenesis.
Topics: Animals; Argonaute Proteins; Azoospermia; Chromatin; DNA Mutational Analysis; DNA-Binding Proteins; Disease Models, Animal; Female; Gene Knock-In Techniques; Histones; Humans; Introns; Male; Mice; Mutation; Pedigree; Protamines; Proteolysis; Spermatogenesis; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 28552346
DOI: 10.1016/j.cell.2017.04.034 -
Nanomaterials (Basel, Switzerland) Jun 2021Macromolecular biomolecules are currently dethroning classical small molecule therapeutics because of their improved targeting and delivery properties. Protamine-a small... (Review)
Review
Macromolecular biomolecules are currently dethroning classical small molecule therapeutics because of their improved targeting and delivery properties. Protamine-a small polycationic peptide-represents a promising candidate. In nature, it binds and protects DNA against degradation during spermatogenesis due to electrostatic interactions between the negatively charged DNA-phosphate backbone and the positively charged protamine. Researchers are mimicking this technique to develop innovative nanopharmaceutical drug delivery systems, incorporating protamine as a carrier for biologically active components such as DNA or RNA. The first part of this review highlights ongoing investigations in the field of protamine-associated nanotechnology, discussing the self-assembling manufacturing process and nanoparticle engineering. Immune-modulating properties of protamine are those that lead to the second key part, which is protamine in novel vaccine technologies. Protamine-based RNA delivery systems in vaccines (some belong to the new class of mRNA-vaccines) against infectious disease and their use in cancer treatment are reviewed, and we provide an update on the current state of latest developments with protamine as pharmaceutical excipient for vaccines.
PubMed: 34200384
DOI: 10.3390/nano11061508 -
Pharmaceutics Jun 2021Protamine is a natural cationic peptide mixture mostly known as a drug for the neutralization of heparin and as a compound in formulations of slow-release insulin.... (Review)
Review
Protamine is a natural cationic peptide mixture mostly known as a drug for the neutralization of heparin and as a compound in formulations of slow-release insulin. Protamine is also used for cellular delivery of nucleic acids due to opposite charge-driven coupling. This year marks 60 years since the first use of Protamine as a transfection enhancement agent. Since then, Protamine has been broadly used as a stabilization agent for RNA delivery. It has also been involved in several compositions for RNA-based vaccinations in clinical development. Protamine stabilization of RNA shows double functionality: it not only protects RNA from degradation within biological systems, but also enhances penetration into cells. A Protamine-based RNA delivery system is a flexible and versatile platform that can be adjusted according to therapeutic goals: fused with targeting antibodies for precise delivery, digested into a cell penetrating peptide for better transfection efficiency or not-covalently mixed with functional polymers. This manuscript gives an overview of the strategies employed in protamine-based RNA delivery, including the optimization of the nucleic acid's stability and translational efficiency, as well as the regulation of its immunostimulatory properties from early studies to recent developments.
PubMed: 34198550
DOI: 10.3390/pharmaceutics13060877 -
EMBO Reports Jun 2023Spermatozoa have a unique genome organization. Their chromatin is almost completely devoid of histones and is formed instead of protamines, which confer a high level of...
Spermatozoa have a unique genome organization. Their chromatin is almost completely devoid of histones and is formed instead of protamines, which confer a high level of compaction and preserve paternal genome integrity until fertilization. Histone-to-protamine transition takes place in spermatids and is indispensable for the production of functional sperm. Here, we show that the H3K79-methyltransferase DOT1L controls spermatid chromatin remodeling and subsequent reorganization and compaction of the spermatozoon genome. Using a mouse model in which Dot1l is knocked-out (KO) in postnatal male germ cells, we found that Dot1l-KO sperm chromatin is less compact and has an abnormal content, characterized by the presence of transition proteins, immature protamine 2 forms and a higher level of histones. Proteomic and transcriptomic analyses performed on spermatids reveal that Dot1l-KO modifies the chromatin prior to histone removal and leads to the deregulation of genes involved in flagellum formation and apoptosis during spermatid differentiation. As a consequence of these chromatin and gene expression defects, Dot1l-KO spermatozoa have less compact heads and are less motile, which results in impaired fertility.
Topics: Animals; Male; Cell Differentiation; Chromatin; Chromatin Assembly and Disassembly; Gene Expression; Histones; Proteomics; Semen; Spermatogenesis; Spermatozoa; Mice
PubMed: 37099396
DOI: 10.15252/embr.202256316