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Frydman GH, Tessier SN, Wong KHK, Vanderburg CR, Fox JG, Toner M, Tompkins RG, Irimia D. Megakaryocytes contain extranuclear histones and may be a source of platelet-associated histones during sepsis. Sci Rep 2020; 10:4621. [PMID: 32165642 PMCID: PMC7067782 DOI: 10.1038/s41598-020-61309-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/24/2020] [Indexed: 12/31/2022] Open
Abstract
Histones are typically located within the intracellular compartment, and more specifically, within the nucleus. When histones are located within the extracellular compartment, they change roles and become damage-associated molecular patterns (DAMPs), promoting inflammation and coagulation. Patients with sepsis have increased levels of extracellular histones, which have been shown to correlate with poor prognosis and the development of sepsis-related sequelae, such as end-organ damage. Until now, neutrophils were assumed to be the primary source of circulating histones during sepsis. In this paper, we show that megakaryocytes contain extranuclear histones and transfer histones to their platelet progeny. Upon examination of isolated platelets from patients with sepsis, we identified that patients with sepsis have increased amounts of platelet-associated histones (PAHs), which appear to be correlated with the type of infection. Taken together, these results suggest that megakaryocytes and platelets may be a source of circulating histones during sepsis and should be further explored.
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Affiliation(s)
- Galit H Frydman
- Division of Comparative Medicine and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America. .,BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
| | - Shannon N Tessier
- BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Keith H K Wong
- BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Charles R Vanderburg
- Harvard Neurodiscovery Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - James G Fox
- Division of Comparative Medicine and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Mehmet Toner
- BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Ronald G Tompkins
- BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Daniel Irimia
- BioMEMS Resource Center, Center for Engineering in Medicine, and Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
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Szymanski PT, Ferguson DG, Paul RJ. Polylysine binding to unphosphorylated smooth muscle myosin enhances formation and stabilizes myosin filaments in vitro. ACTA PHYSIOLOGICA SCANDINAVICA 2002; 174:337-46. [PMID: 11942921 DOI: 10.1046/j.1365-201x.2002.00950.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previously, we demonstrated that positively charged polylysine, our model for biological polyamines, activates the Mg2+ ATPase activity of unphosphorylated smooth muscle myosin and shifts the myosin conformation from the folded 10S to linear 6S form. These effects of polylysine were reversed by the oppositely charged heparin (Szymanski et al. (1993) Am J Physiol 265, C379). In the present report, we provide further information on polylysine binding to smooth muscle myosin, and test the hypothesis that polylysine binding to unphosphorylated myosin involves filament formation. To relate the effects of polylysine on contractility in smooth muscle to physiologically relevant material, we investigated the ability of naturally occurring positively charged polyamines, histones, cadaverine, putrescine and spermidine to activate the Mg2+ ATPase activity of unphosphorylated smooth muscle myosin. Our data show that polylysine binding to individual unphosphorylated myosin molecules stimulates formation of myosin filaments. Polylysine also interacts with myosin filaments, causing enhancement of their size and the numbers, and this could be reversed by heparin. Polylysine binding to myosin filaments made them more resistant to disassembly by high salt concentrations (KCl) or ATP. Naturally occurring polyamines in millimolar concentrations activate the Mg2+ ATPase activity of unphosphorylated smooth muscle myosin. We suggest that the electrostatic interactions between naturally occurring positively charged polyamines and unphosphorylated smooth muscle myosin may play a role in stabilization of thick filament structurein situ.
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Affiliation(s)
- P T Szymanski
- Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0576, USA
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Lehman W. 35 kDa proteins are not components of vertebrate smooth muscle thin filaments. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 996:57-61. [PMID: 2736259 DOI: 10.1016/0167-4838(89)90094-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A 35 kDa protein present in vertebrate smooth muscle and capable of binding to purified actin does not appear to be a constituent of smooth-muscle thin filaments in vivo; instead, it is more likely to be a component easily solubilized from particulate material which then spuriously interacts with actin.
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Affiliation(s)
- W Lehman
- Department of Physiology, Boston University School of Medicine, MA 02118
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Abstract
Contraction in vertebrate smooth and striated muscles results from the interaction of the actin filaments with crossbridges arising from the myosin filaments. The functions of the actin based thin filaments are (1) interaction with myosin to produce force; (2) regulation of force generation in response to Ca2+ concentration; and (3) transmission of the force to the ends of the cell. The major protein components of smooth muscle thin filaments are actin, tropomyosin and caldesmon, present in molar ratios of 28:4:1 respectively. Other smooth muscle proteins which may be associated with the thin filaments in the cell are filamin, vinculin, alpha-actinin, myosin light chain kinase and calmodulin. We have reviewed the structural and functional properties of these proteins and where possible we have suggested what their function and mechanism of action may be. We propose that actin and tropomyosin are involved in the force producing interaction with myosin, and that this interaction is controlled by a Ca2+-dependent mechanism involving caldesmon, tropomyosin and calmodulin. Vinculin, alpha-actinin and filamin appear to be involved in the attachment of the thin filaments to the cell membrane and their spatial organization within the cell. We conclude that the filaments of smooth muscles share many common properties with those from skeletal muscle, but that they are also quite distinct in terms of both their caldesmon based regulatory mechanism and their mode of organization into a contractile apparatus.
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Marston SB, Lehman W. Caldesmon is a Ca2+-regulatory component of native smooth-muscle thin filaments. Biochem J 1985; 231:517-22. [PMID: 2934055 PMCID: PMC1152781 DOI: 10.1042/bj2310517] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Thin-filament preparations from four smooth muscle types (gizzard, stomach, trachea, aorta) all activate myosin MgATPase activity, are regulated by Ca2+, and contain actin, tropomyosin and a 120000-140000-Mr protein in the molar proportions 1:1/7:1/26. The 120000-140000-Mr protein from all sources is a potent inhibitor of actomyosin ATPase activity. Peptide-mapping and immunological evidence is presented showing that it is identical with caldesmon. Quantitative immunological data suggest that caldesmon is a component of all the thin filaments and that the thin-filament-bound caldesmon accounts for all the caldesmon in intact tissue. The myosin light-chain kinase content of thin-filament preparations was found to be negligible. We propose that caldesmon-based thin-filament Ca2+ regulation is a physiological mechanism in all smooth muscles.
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