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1.
EBioMedicine ; 73: 103672, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1568646

ABSTRACT

BACKGROUND: Phospho-Akt1 (pAkt1) undergoes prolyl hydroxylation at Pro125 and Pro313 by the prolyl hydroxylase-2 (PHD2) in a reaction decarboxylating α-ketoglutarate (αKG). We investigated whether the αKG supplementation could inhibit Akt-mediated activation of platelets and monocytes, in vitro as well as in vivo, by augmenting PHD2 activity. METHODS: We treated platelets or monocytes isolated from healthy individuals with αKG in presence of agonists in vitro and assessed the signalling molecules including pAkt1. We supplemented mice with dietary αKG and estimated the functional responses of platelets and monocytes ex vivo. Further, we investigated the impact of dietary αKG on inflammation and thrombosis in lungs of mice either treated with thrombosis-inducing agent carrageenan or infected with SARS-CoV-2. FINDINGS: Octyl αKG supplementation to platelets promoted PHD2 activity through elevated intracellular αKG to succinate ratio, and reduced aggregation in vitro by suppressing pAkt1(Thr308). Augmented PHD2 activity was confirmed by increased hydroxylated-proline and enhanced binding of PHD2 to pAkt in αKG-treated platelets. Contrastingly, inhibitors of PHD2 significantly increased pAkt1 in platelets. Octyl-αKG followed similar mechanism in monocytes to inhibit cytokine secretion in vitro. Our data also describe a suppressed pAkt1 and reduced activation of platelets and leukocytes ex vivo from mice supplemented with dietary αKG, unaccompanied by alteration in their number. Dietary αKG significantly reduced clot formation and leukocyte accumulation in various organs including lungs of mice treated with thrombosis-inducing agent carrageenan. Importantly, in SARS-CoV-2 infected hamsters, we observed a significant rescue effect of dietary αKG on inflamed lungs with significantly reduced leukocyte accumulation, clot formation and viral load alongside down-modulation of pAkt in the lung of the infected animals. INTERPRETATION: Our study suggests that dietary αKG supplementation prevents Akt-driven maladies such as thrombosis and inflammation and rescues pathology of COVID19-infected lungs. FUNDING: Study was funded by the Department of Biotechnology (DBT), Govt. of India (grants: BT/PR22881 and BT/PR22985); and the Science and Engineering Research Board, Govt. of India (CRG/000092).


Subject(s)
Ketoglutaric Acids/therapeutic use , Prolyl Hydroxylases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Thrombosis/prevention & control , Animals , Blood Platelets/cytology , Blood Platelets/drug effects , Blood Platelets/metabolism , COVID-19/pathology , COVID-19/prevention & control , COVID-19/veterinary , COVID-19/virology , Cricetinae , Dietary Supplements , Down-Regulation/drug effects , Humans , Ketoglutaric Acids/pharmacology , Lung/metabolism , Lung/pathology , Mesocricetus , Mice , Mice, Inbred BALB C , Monocytes/cytology , Monocytes/drug effects , Monocytes/metabolism , Phosphorylation , Platelet Aggregation/drug effects , Protein Isoforms/genetics , Protein Isoforms/metabolism , Proto-Oncogene Proteins c-akt/genetics , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Thrombosis/chemically induced , Thrombosis/pathology , Thrombosis/veterinary
3.
Nat Commun ; 12(1): 5552, 2021 09 21.
Article in English | MEDLINE | ID: covidwho-1434105

ABSTRACT

Sepsis is a life-threatening condition caused by the extreme release of inflammatory mediators into the blood in response to infection (e.g., bacterial infection, COVID-19), resulting in the dysfunction of multiple organs. Currently, there is no direct treatment for sepsis. Here we report an abiotic hydrogel nanoparticle (HNP) as a potential therapeutic agent for late-stage sepsis. The HNP captures and neutralizes all variants of histones, a major inflammatory mediator released during sepsis. The highly optimized HNP has high capacity and long-term circulation capability for the selective sequestration and neutralization of histones. Intravenous injection of the HNP protects mice against a lethal dose of histones through the inhibition of platelet aggregation and migration into the lungs. In vivo administration in murine sepsis model mice results in near complete survival. These results establish the potential for synthetic, nonbiological polymer hydrogel sequestrants as a new intervention strategy for sepsis therapy and adds to our understanding of the importance of histones to this condition.


Subject(s)
Hydrogels/therapeutic use , Nanoparticles/therapeutic use , Sepsis/drug therapy , Animals , Blood Platelets/drug effects , Cell Adhesion , Cell Survival/drug effects , Disease Models, Animal , Histones/antagonists & inhibitors , Histones/metabolism , Histones/toxicity , Hydrogels/chemistry , Hydrogels/metabolism , Hydrogels/pharmacology , Lung/drug effects , Lung/metabolism , Lung/pathology , Mice , Nanoparticles/chemistry , Nanoparticles/metabolism , Platelet Aggregation/drug effects , Polyethylene Glycols/chemistry , Polyethylene Glycols/metabolism , Polyethylene Glycols/pharmacology , Polyethylene Glycols/therapeutic use , Protein Binding , Sepsis/mortality , Survival Rate
5.
Mar Drugs ; 19(1)2021 Jan 10.
Article in English | MEDLINE | ID: covidwho-1033055

ABSTRACT

Microalgae are at the start of the food chain, and many are known producers of a significant amount of lipids with essential fatty acids. However, the bioactivity of microalgal lipids for anti-inflammatory and antithrombotic activities have rarely been investigated. Therefore, for a sustainable source of the above bioactive lipids, the present study was undertaken. The total lipids of microalga Chlorococcum sp., isolated from the Irish coast, were fractionated into neutral-, glyco-, and phospho-lipids, and were tested in vitro for their anti-inflammatory and antithrombotic activities. All tested lipid fractions showed strong anti-platelet-activating factor (PAF) and antithrombin activities in human platelets (half maximal inhibitory concentration (IC50) values ranging ~25-200 µg of lipid) with the highest activities in glyco- and phospho-lipid fractions. The structural analysis of the bioactive lipid fraction-2 revealed the presence of specific sulfoquinovosyl diacylglycerols (SQDG) bioactive molecules and the HexCer-t36:2 (t18:1/18:1 and 18:2/18:0) cerebrosides with a phytosphingosine (4-hydrosphinganine) base, while fraction-3 contained bioactive phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules. These novel bioactive lipids of Chlorococcum sp. with putative health benefits may indicate that marine microalgae can be a sustainable alternative source for bioactive lipids production for food supplements and nutraceutical applications. However, further studies are required towards the commercial technology pathways development and biosafety analysis for the use of the microalga.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacology , Lipids/chemistry , Lipids/pharmacology , Microalgae/chemistry , Antithrombins/pharmacology , Blood Platelets/drug effects , Fatty Acids/chemistry , Fatty Acids/pharmacology , Humans , Platelet Activating Factor/antagonists & inhibitors , Platelet Aggregation/drug effects , Water Microbiology
6.
Nitric Oxide ; 107: 11-18, 2021 02 01.
Article in English | MEDLINE | ID: covidwho-949808

ABSTRACT

Nitric oxide, NO, has been explored as a therapeutic agent to treat thrombosis. In particular, NO has potential in treating mechanical device-associated thrombosis due to its ability to reduce platelet activation and due to the central role of platelet activation and adhesion in device thrombosis. Nitrite is a unique NO donor that reduces platelet activation in that it's activity requires the presence of red blood cells whereas NO activity of other NO donors is blunted by red blood cells. Interestingly, we have previously shown that red blood cell mediated inhibition of platelet activation by adenosine diphosophate (ADP) is dramatically enhanced by illumination with far-red light that is likely due to photolysis of red cell surface bound NO congeners. We now report the effects of nitrite, far-red light, and their combination on several measure of blood coagulation using a variety of agonists. We employed turbidity assays in platelet rich plasma, platelet activation using flow cytometry analysis of a fluorescently labeled antibody to the activated platelet fibrinogen binding site, multiplate impedance-based platelet aggregometry, and assessment of platelet adhesion to collagen coated flow-through microslides. In all cases, the combination of far-red light and nitrite treatment decreased measures of coagulation, but in some cases mono-treatment with nitrite or light alone had no effect. Perhaps most relevant to device thrombosis, we observed that platelet adhesions was inhibited by the combination of nitrite and light treatment while nitrite alone and far-red light alone trended to decrease adhesion, but the results were mixed. These results support the potential of combined far-red light and nitrite treatment for preventing thrombosis in extra-corporeal or shallow-tissue depth devices where the far-red light can penetrate. Such a combined treatment could be advantageous due to the localized treatment afforded by far-red light illumination with minimal systemic effects. Given the role of thrombosis in COVID 19, application to treatment of patients infected with SARS Cov-2 might also be considered.


Subject(s)
Blood Coagulation/drug effects , Blood Coagulation/radiation effects , Nitric Oxide Donors/pharmacology , Nitrites/pharmacology , Blood Platelets/drug effects , Blood Platelets/radiation effects , COVID-19/drug therapy , COVID-19/radiotherapy , Humans , Light , Nitric Oxide/metabolism , Platelet Activation/drug effects , Platelet Activation/radiation effects , Platelet Adhesiveness/drug effects , Platelet Adhesiveness/radiation effects , Platelet Aggregation/drug effects , Platelet Aggregation/radiation effects , SARS-CoV-2/drug effects
8.
Adv Rheumatol ; 60(1): 32, 2020 06 09.
Article in English | MEDLINE | ID: covidwho-591986

ABSTRACT

Hydroxychloroquine and chloroquine, also known as antimalarial drugs, are widely used in the treatment of rheumatic diseases and have recently become the focus of attention because of the ongoing COVID-19 pandemic. Rheumatologists have been using antimalarials to manage patients with chronic immune-mediated inflammatory rheumatic diseases for decades. It is an appropriate time to review their immunomodulatory and anti-inflammatory mechanisms impact on disease activity and survival of systemic lupus erythematosus patient, including antiplatelet effect, metabolic and lipid benefits. We also discuss possible adverse effects, adding a practical and comprehensive approach to monitoring rheumatic patients during treatment with these drugs.


Subject(s)
Antimalarials/pharmacology , Arthritis, Rheumatoid/drug therapy , Chloroquine/pharmacology , Hydroxychloroquine/pharmacology , Lupus Erythematosus, Systemic/drug therapy , Antiphospholipid Syndrome/drug therapy , Antiphospholipid Syndrome/immunology , Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/immunology , COVID-19 , Coronavirus Infections/drug therapy , Drug Eruptions/etiology , Drug Interactions , Female , Glucose/metabolism , Heart Diseases/chemically induced , Humans , Lipids/blood , Lupus Erythematosus, Cutaneous/drug therapy , Lupus Erythematosus, Cutaneous/immunology , Lupus Erythematosus, Systemic/immunology , Lupus Erythematosus, Systemic/mortality , Male , Pandemics , Platelet Aggregation/drug effects , Pneumonia, Viral/drug therapy , Pregnancy , Renal Insufficiency/prevention & control , Retinal Diseases/chemically induced , Sjogren's Syndrome/drug therapy , Sjogren's Syndrome/immunology
9.
Platelets ; 31(6): 825-826, 2020 Aug 17.
Article in English | MEDLINE | ID: covidwho-175733

ABSTRACT

EDTA dependent pseudothrombocytopenia (EDTA-PCTP) is a phenomenon that characterized by a spurious decrease of platelets in vitro due to the aggregation of platelets in EDTA anticoagulant blood samples. We report the first case of a transient appearance of EDTA-PCTP in a patient with 2019 novel coronavirus pneumonia (COVID-19). A 59-year-old woman was admitted to the isolated ward for severe type of 2019 novel coronavirus pneumonia. At the time of admission, her platelet count was in a normal range. Two days later, her platelet count decreased gradually without any signs or symptoms of bleeding. Since the peripheral blood smear showed a platelet aggregation, a blood sample anticoagulanted with citrate was tested and the number of platelet was normal. The phenomenon disappeared after 17 days when the patient was cured. This case emphasized the importance of peripheral blood smear and clinical manifestation, especially in the differential diagnosis of thrombocytopenia.


Subject(s)
Betacoronavirus , Blood Platelets/drug effects , Coronavirus Infections/blood , Diagnostic Errors , Edetic Acid/pharmacology , Pandemics , Platelet Aggregation/drug effects , Platelet Count , Pneumonia, Viral/blood , Thrombocytopenia/diagnosis , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/complications , False Positive Reactions , Female , Humans , Middle Aged , Platelet Transfusion , Pneumonia, Viral/complications , SARS-CoV-2 , Unnecessary Procedures
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