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Abstract
PURPOSE OF REVIEW Activated protein C (APC) is a homeostatic coagulation protease with anticoagulant and cytoprotective activities. Focusing on APC's effects in the brain, this review discusses three different scenarios that illustrate how APC functions are intimately affecting the physiology and pathophysiology of the brain. RECENT FINDINGS Cytoprotective APC therapy holds promise for the treatment of ischemic stroke, and a recently completed trial suggested that cytoprotective-selective 3K3A-APC reduced bleeding in ischemic stroke patients. In contrast, APC's anticoagulant activity contributes to brain bleeding as shown by the disproportional upregulation of APC generation in cerebral cavernous malformations lesions in mice. However, too little APC generation also contributes to maladies of the brain, such as in case of cerebral malaria where the binding of infected erythrocytes to the endothelial protein C receptor (EPCR) may interfere with the EPCR-dependent functions of the protein C pathway. Furthermore, discoveries of new activities of APC such as the inhibition of the NLRP3-mediated inflammasome and of new applications of APC therapy such as in Alzheimer's disease and graft-versus-host disease continue to advance our knowledge of this important proteolytic regulatory system. SUMMARY APC's many activities or lack thereof are intimately involved in multiple neuropathologies, providing abundant opportunities for translational research.
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Rajput PS, Lamb JA, Fernández JÁ, Bai J, Pereira BR, Lei IF, Leung J, Griffin JH, Lyden PD. Neuroprotection and vasculoprotection using genetically targeted protease-ligands. Brain Res 2019; 1715:13-20. [PMID: 30880117 DOI: 10.1016/j.brainres.2019.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 03/05/2019] [Accepted: 03/13/2019] [Indexed: 12/26/2022]
Abstract
Thrombin and activated protein C (APC) are known coagulation factors that exhibit profound effects in brain by acting on the protease activated receptor (PAR). The wild type (WT) proteases appear to impact cell survival powerfully, and therapeutic forms of APC are under development. Engineered recombinant thrombin or APC were designed to separate their procoagulant or anticoagulant effects from their cytoprotective properties. We measured vascular disruption and neuronal degeneration after a standard rodent filament stroke model. For comparison to a robust anticoagulant, we used a GpIIb/IIIa inhibitor, GR144053. During 2 h MCAo both WT murine APC and its mutant, 5A-APC, significantly decreased neuronal death 30 min after reperfusion. During 4 h MCAo, only 5A-APC significantly protected neurons but both WT-APC and 5A-APC exacerbated vascular disruption during 4 h MCAo. Human APC mutants appeared to reduce 24 h neuronal injury significantly when given after 2 h delay after MCAo. In contrast, 24 h vascular damage was worsened by high doses of WT and mutant APCs, although only statistically significantly for high dose 3K3A-APC. Mutated thrombin worsened vascular damage significantly without affecting neuron damage. GR144053 failed to ameliorate vascular disruption or neuronal injury despite significant anticoagulation. Differential effects on neurons and the vasculature were demonstrated using wild-type and mutated proteases. The mutants murine 3K3A-APC and 5A-APC protected neurons in this rodent model but in high doses worsened vascular leakage. Cytoactive effects of plasma proteases may be separated from their coagulation effects. Further studies should explore impact of dose and timing on cytoactive and vasculoactive properties of these drugs.
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Affiliation(s)
- Padmesh S Rajput
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - Jessica A Lamb
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - Jose Á Fernández
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Jilin Bai
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - Benedict R Pereira
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - I-Farn Lei
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - Jennifer Leung
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States
| | - John H Griffin
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Patrick D Lyden
- Department of Neurology, Cedars Sinai Medical Center, 127 S San Vicente Blvd, Los Angeles, CA 90048, United States.
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Activated Protein C in Cutaneous Wound Healing: From Bench to Bedside. Int J Mol Sci 2019; 20:ijms20040903. [PMID: 30791425 PMCID: PMC6412604 DOI: 10.3390/ijms20040903] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/14/2019] [Accepted: 02/16/2019] [Indexed: 12/12/2022] Open
Abstract
Independent of its well-known anticoagulation effects, activated protein C (APC) exhibits pleiotropic cytoprotective properties. These include anti-inflammatory actions, anti-apoptosis, and endothelial and epithelial barrier stabilisation. Such beneficial effects have made APC an attractive target of research in a plethora of physiological and pathophysiological processes. Of note, the past decade or so has seen the emergence of its roles in cutaneous wound healing-a complex process involving inflammation, proliferation and remodelling. This review will highlight APC's functions and mechanisms, and detail its pre-clinical and clinical studies on cutaneous wound healing.
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Can adjunctive therapies augment the efficacy of endovascular thrombolysis? A potential role for activated protein C. Neuropharmacology 2017; 134:293-301. [PMID: 28923278 DOI: 10.1016/j.neuropharm.2017.09.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022]
Abstract
In the management of acute ischemic stroke, vessel recanalization correlates with functional status, mortality, cost, and other outcome measures. Thrombolysis with intravenous tissue plasminogen activator has many limitations that restrict its applicability, but recent advances in the development of mechanical thrombectomy devices as well as improved systems of stroke care have resulted in greater likelihood of vessel revascularization. Nonetheless, there remains substantial discrepancy between rates of recanalization and rates of favorable outcome. The poor neurological recovery among some stroke patients despite successful recanalization confirms the need for adjuvant pharmacological therapy for neuroprotection and/or neurorestoration. Prior clinical trials of such drugs may have failed due to the inability of the agent to access the ischemic tissue beyond the occluded artery. A protocol that couples revascularization with concurrent delivery of a neuroprotectant drug offers the potential to enhance the benefit of thrombolysis. Analogs of activated protein C (APC) exert pleiotropic anti-inflammatory, anti-apoptotic, antithrombotic, cytoprotective, and neuroregenerative effects in ischemic stroke and thus appear to be promising candidates for this novel approach. A multicenter, prospective, double-blinded, dose-escalation Phase 2 randomized clinical trial has enrolled 110 patients to assess the safety, pharmacokinetics, and efficacy of human recombinant 3K3A-APC following endovascular thrombolysis. This article is part of the Special Issue entitled 'Cerebral Ischemia'.
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Griffin JH, Fernández JA, Lyden PD, Zlokovic BV. Activated protein C promotes neuroprotection: mechanisms and translation to the clinic. Thromb Res 2017; 141 Suppl 2:S62-4. [PMID: 27207428 DOI: 10.1016/s0049-3848(16)30368-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Activated protein C (APC) is a plasma serine protease that is capable of antithrombotic, anti-inflammatory, anti-apoptotic, and cell-signaling activities. Animal injury studies show that recombinant APC and some of its mutants are remarkably therapeutic for a wide range of injuries. In particular, for neurologic injuries, APC reduces damage caused by ischemia/reperfusion in the brain, by acute brain trauma, and by chronic neurodegenerative conditions. For these neuroprotective effects, APC requires endothelial cell protein C receptor. APC activates cell signaling networks with alterations in gene expression profiles by activating protease activated receptors 1 and 3. To minimize APC-induced bleeding risk, APC variants were engineered to lack > 90% anticoagulant activity but retain normal cell signaling. The neuroprotective APC mutant, 3K3A-APC which has Lys191-193 mutated to Ala191-193, is very neuroprotective and it is currently in clinical trials for ischemic stroke.
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Affiliation(s)
- John H Griffin
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA; Department of Medicine, Division of Hematology/Oncology, University of California San Diego, San Diego, CA, USA.
| | - José A Fernández
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Patrick D Lyden
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Berislav V Zlokovic
- Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, CA; Department of Neurosurgery, Zilkha Neurogenetic Institute, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA
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Griffin JH, Mosnier LO, Fernández JA, Zlokovic BV. 2016 Scientific Sessions Sol Sherry Distinguished Lecturer in Thrombosis: Thrombotic Stroke: Neuroprotective Therapy by Recombinant-Activated Protein C. Arterioscler Thromb Vasc Biol 2016; 36:2143-2151. [PMID: 27758767 PMCID: PMC5119536 DOI: 10.1161/atvbaha.116.308038] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 09/21/2016] [Indexed: 01/19/2023]
Abstract
APC (activated protein C), derived from the plasma protease zymogen, is antithrombotic and anti-inflammatory. In preclinical injury models, recombinant APC provides neuroprotection for multiple injuries, including ischemic stroke. APC acts directly on brain endothelial cells and neurons by initiating cell signaling that requires multiple receptors. Two or more major APC receptors mediate APC's neuroprotective cell signaling. When bound to endothelial cell protein C receptor, APC can cleave protease-activated receptor 1, causing biased cytoprotective signaling that reduces ischemia-induced injury. Pharmacological APC alleviates bleeding induced by tissue-type plasminogen activator in murine ischemic stroke studies. Remarkably, APC's signaling promotes neurogenesis. The signaling-selective recombinant variant of APC, 3K3A-APC, was engineered to lack most of the APC's anticoagulant activity but retain APC's cell signaling actions. Recombinant 3K3A-APC is in ongoing National Institutes of Health (NIH)-funded clinical trials for ischemic stroke.
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Affiliation(s)
- John H Griffin
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA (J.H.G., L.O.M., J.A.F.); Division of Hematology/Oncology, Department of Medicine, University of California, San Diego (J.H.G.); and Department of Physiology and Biophysics, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles (B.V.Z.).
| | - Laurent O Mosnier
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA (J.H.G., L.O.M., J.A.F.); Division of Hematology/Oncology, Department of Medicine, University of California, San Diego (J.H.G.); and Department of Physiology and Biophysics, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles (B.V.Z.)
| | - José A Fernández
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA (J.H.G., L.O.M., J.A.F.); Division of Hematology/Oncology, Department of Medicine, University of California, San Diego (J.H.G.); and Department of Physiology and Biophysics, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles (B.V.Z.)
| | - Berislav V Zlokovic
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA (J.H.G., L.O.M., J.A.F.); Division of Hematology/Oncology, Department of Medicine, University of California, San Diego (J.H.G.); and Department of Physiology and Biophysics, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles (B.V.Z.)
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Verbout NG, Yu X, Healy LD, Phillips KG, Tucker EI, Gruber A, McCarty OJT, Offner H. Thrombin mutant W215A/E217A treatment improves neurological outcome and attenuates central nervous system damage in experimental autoimmune encephalomyelitis. Metab Brain Dis 2015; 30:57-65. [PMID: 24810631 PMCID: PMC4225189 DOI: 10.1007/s11011-014-9558-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/28/2014] [Indexed: 10/25/2022]
Abstract
Multiple sclerosis (MS) is a neuroinflammatory disease characterized by demyelination and axonal damage of the central nervous system. The pathogenesis of MS has also been linked to vascular inflammation and local activation of the coagulation system, resulting in perivascular fibrin deposition. Treatment of experimental autoimmune encephalomyelitis (EAE), a model of human MS, with antithrombotic and antiinflammatory activated protein C (APC) reduces disease severity. Since recombinant APC (Drotecogin alfa), originally approved for the treatment of severe sepsis, is not available for human MS studies, we tested the hypothesis that pharmacologic activation of endogenous protein C could likewise improve the outcome of EAE. Mice were immunized with murine myelin oligodendrocyte glycoprotein (MOG) peptides and at the onset of EAE symptoms, were treated every other day with either WE thrombin (25 μg/kg; i.v.), a selective recombinant protein C activator thrombin analog, or saline control. Mice were monitored for changes in disease score until euthanized for ex vivo analysis of inflammation. Administration of WE thrombin significantly ameliorated clinical severity of EAE, reduced inflammatory cell infiltration and demyelination, suppressed the activation of macrophages comprising the CD11b + population and reduced accumulation of fibrin (ogen) in the spinal cord. These data suggest that symptomatic MS may respond to a treatment strategy that involves temporal pharmacological enhancement of endogenous APC generation.
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Affiliation(s)
- Norah G Verbout
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, OR, 97239, USA,
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Mosnier LO, Zlokovic BV, Griffin JH. Cytoprotective-selective activated protein C therapy for ischaemic stroke. Thromb Haemost 2014; 112:883-92. [PMID: 25230930 DOI: 10.1160/th14-05-0448] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/05/2014] [Indexed: 12/14/2022]
Abstract
Despite years of research and efforts to translate stroke research to clinical therapy, ischaemic stroke remains a major cause of death, disability, and diminished quality of life. Primary and secondary preventive measures combined with improved quality of care have made significant progress. However, no novel drug for ischaemic stroke therapy has been approved in the past decade. Numerous studies have shown beneficial effects of activated protein C (APC) in rodent stroke models. In addition to its natural anticoagulant functions, APC conveys multiple direct cytoprotective effects on many different cell types that involve multiple receptors including protease activated receptor (PAR) 1, PAR3, and the endothelial protein C receptor (EPCR). Application of molecular engineered APC variants with altered selectivity profiles to rodent stroke models demonstrated that the beneficial effects of APC primarily require its cytoprotective activities but not its anticoagulant activities. Extensive basic, preclinical, and clinical research provided a compelling rationale based on strong evidence for translation of APC therapy that has led to the clinical development of the cytoprotective-selective APC variant, 3K3A-APC, for ischaemic stroke. Recent identification of non-canonical PAR1 and PAR3 activation by APC that give rise to novel tethered-ligands capable of inducing biased cytoprotective signalling as opposed to the canonical signalling provides a mechanistic explanation for how APC-mediated PAR activation can selectively induce cytoprotective signalling pathways. Collectively, these paradigm-shifting discoveries provide detailed insights into the receptor targets and the molecular mechanisms for neuroprotection by cytoprotective-selective 3K3A-APC, which is currently a biologic drug in clinical trials for ischaemic stroke.
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Affiliation(s)
- Laurent O Mosnier
- Laurent O. Mosnier, PhD, Department of Molecular and Experimental Medicine (MEM-180), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA, Tel.: +1 858 784 2227, Fax: +1 858 784 2243, E-mail:
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Wildhagen KCAA, Schrijver R, Beckers L, ten Cate H, Reutelingsperger CPM, Lutgens E, Nicolaes GAF. Effects of exogenous recombinant APC in mouse models of ischemia reperfusion injury and of atherosclerosis. PLoS One 2014; 9:e101446. [PMID: 25032959 PMCID: PMC4102480 DOI: 10.1371/journal.pone.0101446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/06/2014] [Indexed: 01/12/2023] Open
Abstract
Activated protein C (APC) is a serine protease that has both anticoagulant and cytoprotective properties. The cytoprotective effects are protease activated receptor 1 (PAR-1) and endothelial protein C receptor (EPCR) dependent and likely underlie protective effects of APC in animal models of sepsis, myocardial infarction and ischemic stroke. S360A-(A)PC, a variant (A)PC that has no catalytic activity, binds EPCR and shifts pro-inflammatory signaling of the thrombin-PAR-1 complex to anti-inflammatory signaling. In this study we investigated effects of human (h)wt-PC, hS360A-PC, hwt-APC and hS360A-APC in acute (mouse model of acute myocardial ischemia/reperfusion (I/R) injury) and chronic inflammation (apoE-/- mouse model of atherosclerosis). All h(A)PC variants significantly reduced myocardial infarct area (p<0.05) following I/R injury. IL-6 levels in heart homogenates did not differ significantly between sham, placebo and treatment groups in I/R injury. None of the h(A)PC variants decreased number and size of atherosclerotic plaques in apoE-/- mice. Only hS360A-APC slightly affected phenotype of plaques. IL-6 levels in plasma were significantly (p<0.001) decreased in hwt-APC and hS360A-PC treated mice. In the last group levels of monocyte chemotactic protein 1 (MCP-1) were significantly increased (p<0.05). In this study we show that both hwt and hS360A-(A)PC protect against acute myocardial I/R injury, which implies that protection from I/R injury is independent of the proteolytic activity of APC. However, in the chronic atherosclerosis model hwt and hS360-(A)PC had only minor effects. When the dose, species and mode of (A)PC administration will be adjusted, we believe that (A)PC will have potential to influence development of chronic inflammation as occurring during atherosclerosis as well.
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Affiliation(s)
- Karin C. A. A. Wildhagen
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Roy Schrijver
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Linda Beckers
- Department of Medical Biochemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - Hugo ten Cate
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
- Department of Internal Medicine, Laboratory for Clinical Thrombosis and Haemostasis, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Chris P. M. Reutelingsperger
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Esther Lutgens
- Department of Medical Biochemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - Gerry A. F. Nicolaes
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
- * E-mail:
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