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Schwertz H, Middleton EA. Autophagy and its consequences for platelet biology. Thromb Res 2023; 231:170-181. [PMID: 36058760 PMCID: PMC10286736 DOI: 10.1016/j.thromres.2022.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/26/2022] [Accepted: 08/19/2022] [Indexed: 01/18/2023]
Abstract
Autophagy, the continuous recycling of intracellular building blocks, molecules, and organelles is necessary to preserve cellular function and homeostasis. In this context, it was demonstrated that autophagy plays an important role in megakaryopoiesis, the development and differentiation of hematopoietic progenitor cells into megakaryocytes. Furthermore, in recent years, autophagic proteins were detected in platelets, anucleate cells generated by megakaryocytes, responsible for hemostasis, thrombosis, and a key cell in inflammation and host immune responses. In the last decade studies have indicated the occurrence of autophagy in platelets. Moreover, autophagy in platelets was subsequently demonstrated to be involved in platelet aggregation, adhesion, and thrombus formation. Here, we review the current knowledge about autophagy in platelets, its function, and clinical implications. However, at the advent of platelet autophagy research, additional discoveries derived from evolving work will be required to precisely define the contributions of autophagy in platelets, and to expand the ever increasing physiologic and pathologic roles these remarkable and versatile blood cells play.
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Affiliation(s)
- Hansjörg Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Division of Occupational Medicine, University of Utah, Salt Lake City, UT 84112, USA; Department of Occupational Medicine, Billings Clinic Bozeman, Bozeman, MT 59718, USA.
| | - Elizabeth A Middleton
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Division of Pulmonary Medicine and Critical Care, University of Utah, Salt Lake City, UT 84112, USA
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Freitag M, Schwertz H. A New Role of NAP1L1 in Megakaryocytes and Human Platelets. Int J Mol Sci 2022; 23:ijms232314694. [PMID: 36499021 PMCID: PMC9737020 DOI: 10.3390/ijms232314694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/26/2022] Open
Abstract
Platelets (PLTs) are anucleate and considered incapable of nuclear functions. Contrastingly, nuclear proteins were detected in human PLTs. For most of these proteins, it is unclear if nuclear or alternatively assigned functions are performed, a question we wanted to address for nuclear assembly protein 1like 1 (NAP1L1). Using a wide array of molecular methods, including RNAseq, co-IP, overexpression and functional assays, we explored expression pattern and functionality of NAP1L1 in PLTs, and CD34+-derived megakaryocytes (MKs). NAP1L1 is expressed in PLTs and MKs. Co-IP experiments revealed that dihydrolipolylysine-residue acetyltransferase (DLAT encoded protein PDC-E2, ODP2) dynamically interacts with NAP1L1. PDC-E2 is part of the mitochondrial pyruvate-dehydrogenase (PDH) multi-enzyme complex, playing a crucial role in maintaining cellular respiration, and promoting ATP-synthesis via the respiratory chain. Since altered mitochondrial function is a hallmark of infectious syndromes, we analyzed PDH activity in PLTs from septic patients demonstrating increased activity, paralleling NAP1L1 expression levels. MKs PDH activity decreased following an LPS-challenge. Furthermore, overexpression of NAP1L1 significantly altered the ability of MKs to form proplatelet extensions, diminishing thrombopoiesis. These results indicate that NAP1L1 performs in other than nucleosome-assembly functions in PTLs and MKs, binding a key mitochondrial protein as a potential chaperone, and gatekeeper, influencing PDH activity and thrombopoiesis.
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Affiliation(s)
- Martin Freitag
- Department of Cardiac Surgery, Heart Center Leipzig-University Hospital, 04289 Leipzig, Germany
| | - Hansjörg Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
- Division of Occupational Medicine, University of Utah, Salt Lake City, UT 84112, USA
- Occupational Medicine at Billings Clinic Bozeman, Bozeman, MT 59715, USA
- Correspondence: or
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Schwertz H, Rowley JW, Portier I, Middleton EA, Tolley ND, Campbell RA, Eustes AS, Chen K, Rondina MT. Human platelets display dysregulated sepsis-associated autophagy, induced by altered LC3 protein-protein interaction of the Vici-protein EPG5. Autophagy 2021; 18:1534-1550. [PMID: 34689707 DOI: 10.1080/15548627.2021.1990669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Platelets mediate central aspects of host responses during sepsis, an acute profoundly systemic inflammatory response due to infection. Macroautophagy/autophagy, which mediates critical aspects of cellular responses during inflammatory conditions, is known to be a functional cellular process in anucleate platelets, and is essential for normal platelet functions. Nevertheless, how sepsis may alter autophagy in platelets has never been established. Using platelets isolated from septic patients and matched healthy controls, we show that during clinical sepsis, the number of autophagosomes is increased in platelets, most likely due to an accumulation of autophagosomes, some containing mitochondria and indicative of mitophagy. Therefore, autophagy induction or early-stage autophagosome formation (as compared to decreased later-stage autophagosome maturation or autophagosome-late endosome/lysosome fusion) is normal or increased. This was consistent with decreased fusion of autophagosomes with lysosomes in platelets. EPG5 (ectopic P-granules autophagy protein 5 homolog), a protein essential for normal autophagy, expression did increase, while protein-protein interactions between EPG5 and MAP1LC3/LC3 (which orchestrate the fusion of autophagosomes and lysosomes) were significantly reduced in platelets during sepsis. Furthermore, data from a megakaryocyte model demonstrate the importance of TLR4 (toll like receptor 4), LPS-dependent signaling for regulating this mechanism. Similar phenotypes were also observed in platelets isolated from a patient with Vici syndrome: an inherited condition caused by a naturally occurring, loss-of-function mutation in EPG5. Together, we provide evidence that autophagic functions are aberrant in platelets during sepsis, due in part to reduced EPG5-LC3 interactions, regulated by TLR4 engagement, and the resultant accumulation of autophagosomes.Abbreviations: ACTB: beta actin; CLP: cecal ligation and puncture; Co-IP: co-immunoprecipitation; DAP: death associated protein; DMSO: dimethyl sulfoxide; EPG5: ectopic P-granules autophagy protein 5 homolog; ECL: enhanced chemiluminescence; HBSS: Hanks' balanced salt solution; HRP: horseradish peroxidase; ICU: intensive care unit; LPS: lipopolysaccharide; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MKs: megakaryocytes; PFA: paraformaldehyde; PBS: phosphate-buffered saline; PLA: proximity ligation assay; pRT-PCR: quantitative real-time polymerase chain reaction; RT: room temperature; SQSTM1/p62: sequestosome 1; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TLR4: toll like receptor 4; TEM: transmission electron microscopy; WGA: wheat germ agglutinin.
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Affiliation(s)
- Hansjörg Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Work Wellness Clinic, University of Utah, Salt Lake City, UT, USA.,Division of Occupational Medicine, University of Utah, Salt Lake City, UT, USA.,Occupational Medicine, Billings Clinic Bozeman, Bozeman, MT, USA
| | - Jesse W Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Division of Pulmonary Medicine, University of Utah, Salt Lake City, UT, USA
| | - Irina Portier
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - Elizabeth A Middleton
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Division of Pulmonary Medicine, University of Utah, Salt Lake City, UT, USA
| | - Neal D Tolley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - Robert A Campbell
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Departments of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Alicia S Eustes
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Department of Internal Medicine, University of Iowa in Iowa City, IA, USA
| | - Karin Chen
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Department of Pediatrics, University of Utah, Salt Lake City, UT, USA.,Department of Pediatrics, University of Washington School of Medicine, and Seattle Children's Hospital, Seattle, WA, USA
| | - Matthew T Rondina
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Departments of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Department of Pathology, University of Utah, Salt Lake City, UT, USA.,Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, Salt Lake City, UT 84112, USA
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Wende AR, Schell JC, Ha CM, Pepin ME, Khalimonchuk O, Schwertz H, Pereira RO, Brahma MK, Tuinei J, Contreras-Ferrat A, Wang L, Andrizzi CA, Olsen CD, Bradley WE, Dell'Italia LJ, Dillmann WH, Litwin SE, Abel ED. Maintaining Myocardial Glucose Utilization in Diabetic Cardiomyopathy Accelerates Mitochondrial Dysfunction. Diabetes 2020; 69:2094-2111. [PMID: 32366681 PMCID: PMC7506832 DOI: 10.2337/db19-1057] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 04/25/2020] [Indexed: 12/13/2022]
Abstract
Cardiac glucose uptake and oxidation are reduced in diabetes despite hyperglycemia. Mitochondrial dysfunction contributes to heart failure in diabetes. It is unclear whether these changes are adaptive or maladaptive. To directly evaluate the relationship between glucose delivery and mitochondrial dysfunction in diabetic cardiomyopathy, we generated transgenic mice with inducible cardiomyocyte-specific expression of the GLUT4. We examined mice rendered hyperglycemic following low-dose streptozotocin prior to increasing cardiomyocyte glucose uptake by transgene induction. Enhanced myocardial glucose in nondiabetic mice decreased mitochondrial ATP generation and was associated with echocardiographic evidence of diastolic dysfunction. Increasing myocardial glucose delivery after short-term diabetes onset exacerbated mitochondrial oxidative dysfunction. Transcriptomic analysis revealed that the largest changes, driven by glucose and diabetes, were in genes involved in mitochondrial function. This glucose-dependent transcriptional repression was in part mediated by O-GlcNAcylation of the transcription factor Sp1. Increased glucose uptake induced direct O-GlcNAcylation of many electron transport chain subunits and other mitochondrial proteins. These findings identify mitochondria as a major target of glucotoxicity. They also suggest that reduced glucose utilization in diabetic cardiomyopathy might defend against glucotoxicity and caution that restoring glucose delivery to the heart in the context of diabetes could accelerate mitochondrial dysfunction by disrupting protective metabolic adaptations.
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Affiliation(s)
- Adam R Wende
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL
| | - John C Schell
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
| | - Chae-Myeong Ha
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL
| | - Mark E Pepin
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL
| | - Oleh Khalimonchuk
- Department of Biochemistry and Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE
| | - Hansjörg Schwertz
- Division of Occupational Medicine, Molecular Medicine Program, and Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, UT
| | - Renata O Pereira
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Manoja K Brahma
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL
| | - Joseph Tuinei
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
| | - Ariel Contreras-Ferrat
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
- Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Li Wang
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
| | - Chase A Andrizzi
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
| | - Curtis D Olsen
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
| | - Wayne E Bradley
- Birmingham Veterans Affairs Medical Center, Birmingham, AL
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL
| | - Louis J Dell'Italia
- Birmingham Veterans Affairs Medical Center, Birmingham, AL
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL
| | | | - Sheldon E Litwin
- Division of Cardiology, University of Utah School of Medicine, Salt Lake City, UT
- Department of Medicine, Medical University of South Carolina, Charleston, SC
- Division of Cardiology, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC
| | - E Dale Abel
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, UT
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA
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Rondina MT, Voora D, Simon LM, Schwertz H, Harper JF, Lee O, Bhatlekar SC, Li Q, Eustes AS, Montenont E, Campbell RA, Tolley ND, Kosaka Y, Weyrich AS, Bray PF, Rowley JW. Longitudinal RNA-Seq Analysis of the Repeatability of Gene Expression and Splicing in Human Platelets Identifies a Platelet SELP Splice QTL. Circ Res 2019; 126:501-516. [PMID: 31852401 DOI: 10.1161/circresaha.119.315215] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
RATIONALE Longitudinal studies are required to distinguish within versus between-individual variation and repeatability of gene expression. They are uniquely positioned to decipher genetic signal from environmental noise, with potential application to gene variant and expression studies. However, longitudinal analyses of gene expression in healthy individuals-especially with regards to alternative splicing-are lacking for most primary cell types, including platelets. OBJECTIVE To assess repeatability of gene expression and splicing in platelets and use repeatability to identify novel platelet expression quantitative trait loci (QTLs) and splice QTLs. METHODS AND RESULTS We sequenced the transcriptome of platelets isolated repeatedly up to 4 years from healthy individuals. We examined within and between individual variation and repeatability of platelet RNA expression and exon skipping, a readily measured alternative splicing event. We find that platelet gene expression is generally stable between and within-individuals over time-with the exception of a subset of genes enriched for the inflammation gene ontology. We show an enrichment among repeatable genes for associations with heritable traits, including known and novel platelet expression QTLs. Several exon skipping events were also highly repeatable, suggesting heritable patterns of splicing in platelets. One of the most repeatable was exon 14 skipping of SELP. Accordingly, we identify rs6128 as a platelet splice QTL and define an rs6128-dependent association between SELP exon 14 skipping and race. In vitro experiments demonstrate that this single nucleotide variant directly affects exon 14 skipping and changes the ratio of transmembrane versus soluble P-selectin protein production. CONCLUSIONS We conclude that the platelet transcriptome is generally stable over 4 years. We demonstrate the use of repeatability of gene expression and splicing to identify novel platelet expression QTLs and splice QTLs. rs6128 is a platelet splice QTL that alters SELP exon 14 skipping and soluble versus transmembrane P-selectin protein production.
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Affiliation(s)
- Matthew T Rondina
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
- George E. Wahlen VAMC Geriatric Research and Education Clinical Center (M.T.R.)
| | - Deepak Voora
- Duke Center for Applied Genomics & Precision Medicine, Durham, NC (D.V.)
| | - Lukas M Simon
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Computational Biology, Neuherberg, Germany (L.M.S.)
| | - Hansjörg Schwertz
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
- Rocky Mountain Center for Occupational and Environmental Health, The University of Utah, Salt Lake City (H.S.)
| | - Julie F Harper
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Olivia Lee
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Seema C Bhatlekar
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Qing Li
- Huntsman Cancer Institute, Salt Lake City, Utah (Q.L.)
| | - Alicia S Eustes
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Emilie Montenont
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Robert A Campbell
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
| | - Neal D Tolley
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Yasuhiro Kosaka
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
| | - Andrew S Weyrich
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
| | - Paul F Bray
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
| | - Jesse W Rowley
- From the Molecular Medicine Program (M.T.R., H.S., J.F.H., O.L., S.C.B., A.S.E., E.M., R.A.C., N.D.T., Y.K., A.S.W., P.F.B., J.W.R.)
- Department of Internal Medicine (M.T.R., H.S., R.A.C., A.S.W., P.F.B., J.W.R.)
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Affiliation(s)
- Hansjörg Schwertz
- University of Utah Molecular Medicine Program, University of Utah, Salt Lake City, UT 84108, USA
- Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, UT 84108, USA
| | - Matthew T Rondina
- University of Utah Molecular Medicine Program, University of Utah, Salt Lake City, UT 84108, USA
- Departments of Internal Medicine and Pathology, University of Utah, Salt Lake City, UT 84108, USA
- Department of Internal Medicine and GRECC at the George E. Wahlen Salt Lake City VAMC in Salt Lake City, UT 84148, USA
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Affiliation(s)
- Hansjörg Schwertz
- Program in Molecular Medicine in Salt Lake City, Utah, USA; Rocky Mountain Center for Occupational and Environmental Health in Salt Lake City, Utah, USA.
| | - Matthew T Rondina
- Program in Molecular Medicine in Salt Lake City, Utah, USA; The Department of Internal Medicine, in Salt Lake City, Utah, USA; University of Utah, Salt Lake City, Utah, USA, and the Department of Internal Medicine at the George E. Wahlen Salt Lake City VAMC in Salt Lake City, Utah, USA
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Schwertz H, Rondina MT. Retinoic acid receptor-α regulates synthetic events in human platelets: reply. J Thromb Haemost 2018; 16:1015-1016. [PMID: 29509307 DOI: 10.1111/jth.13995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Indexed: 11/29/2022]
Affiliation(s)
- H Schwertz
- Department of Internal Medicine and the Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Salt Lake City VAMC, Salt Lake City, UT, USA
| | - M T Rondina
- Department of Internal Medicine and the Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Salt Lake City VAMC, Salt Lake City, UT, USA
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Schwertz H, Rowley JW, Schumann GG, Thorack U, Campbell RA, Manne BK, Zimmerman GA, Weyrich AS, Rondina MT. Endogenous LINE-1 (Long Interspersed Nuclear Element-1) Reverse Transcriptase Activity in Platelets Controls Translational Events Through RNA-DNA Hybrids. Arterioscler Thromb Vasc Biol 2018; 38:801-815. [PMID: 29301786 DOI: 10.1161/atvbaha.117.310552] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 12/11/2017] [Indexed: 12/11/2022]
Abstract
OBJECTIVE One source of endogenous reverse transcriptase (eRT) activity in nucleated cells is the LINE-1/L1 (long interspersed nuclear element-1), a non-LTR retrotransposon that is implicated in the regulation of gene expression. Nevertheless, the presence and function of eRT activity and LINE-1 in human platelets, an anucleate cell, has not previously been determined. APPROACH AND RESULTS We demonstrate that human and murine platelets possess robust eRT activity and identify the source as being LINE-1 ribonucleoprotein particles. Inhibition of eRT in vitro in isolated platelets from healthy individuals or in people with HIV treated with RT inhibitors enhanced global protein synthesis and platelet activation. If HIV patients were treated with reverse transcriptase inhibitor, we found that platelets from these patients had increased basal activation. We next discovered that eRT activity in platelets controlled the generation of RNA-DNA hybrids, which serve as translational repressors. Inhibition of platelet eRT lifted this RNA-DNA hybrid-induced translational block and was sufficient to increase protein expression of target RNAs identified by RNA-DNA hybrid immunoprecipitation. CONCLUSIONS Thus, we provide the first evidence that platelets possess L1-encoded eRT activity. We also demonstrate that platelet eRT activity regulates platelet hyperreactivity and thrombosis and controls RNA-DNA hybrid formation and identify that RNA-DNA hybrids function as a novel translational control mechanism in human platelets.
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Affiliation(s)
- Hansjörg Schwertz
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.).
| | - Jesse W Rowley
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Gerald G Schumann
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Ulrike Thorack
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Robert A Campbell
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Bhanu Kanth Manne
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Guy A Zimmerman
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Andrew S Weyrich
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
| | - Matthew T Rondina
- From the Molecular Medicine Program (H.S., J.W.R., R.A.C., B.K.M., G.A.Z., A.S.W., M.T.R.), Department of Internal Medicine (H.S., J.W.R., G.A.Z., A.S.W., M.T.R.), and Department of Surgery, Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, UT (M.T.R.); Department of Immunology and Transfusion Medicine (U.T.) and Lichtenberg-Professor for Experimental Hemostasis (H.S.), University of Greifswald, Germany; and Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany (G.G.S.)
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10
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Schwertz H, Rowley JW, Zimmerman GA, Weyrich AS, Rondina MT. Retinoic acid receptor-α regulates synthetic events in human platelets. J Thromb Haemost 2017; 15:2408-2418. [PMID: 28981191 DOI: 10.1111/jth.13861] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Indexed: 12/01/2022]
Abstract
Essentials Platelets express retinoic acid receptor (RAR)α protein, specifically binding target mRNAs. mRNAs under RARα control include MAP1LC3B2, SLAIN2, and ANGPT1. All-trans retinoic acid (atRA) releases RARα from its target mRNA. RARα expressed in human platelets exerts translational control via direct mRNA binding. SUMMARY Background Translational control mechanisms in platelets are incompletely defined. Here, we determined whether the nuclear transcription factor RARα controls protein translational events in human platelets. Methods Isolated human platelets were treated with the pan-RAR agonist all-trans-retinoic acid (atRA). Global and targeted translational events were examined. Results Stimulation of platelets with atRA significantly increased global protein expression. RARα protein bound to a subset of platelet mRNAs, as measured by next-generation RNA-sequencing. In-depth analyses of 5' and 3'-untranslated regions of the RARα-bound mRNAs revealed consensus RARα binding sites in microtubule-associated protein 1 light chain 3 beta 2 (MAP1LC3B2), SLAIN motif-containing protein 2 (SLAIN2) and angiopoietin-1 (ANGPT1) transcripts. When platelets were treated with atRA, binding interactions between RARα protein and mRNA for MAP1LC3B2, SLAIN2 and ANGPT1 were significantly decreased. Consistent with the release of bound RARα protein from MAP1LCB2mRNA, we observed an increase in the synthesis of MAP1LC3B2 protein. Conclusions These findings provide the first evidence that RARα, a nuclear transcriptional factor, regulates synthetic events in anucleate human platelets. They also reveal an additional non-genomic role for RARα in platelets that may have implications for the vitamin A-dependent signaling in humans.
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Affiliation(s)
- H Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Departments of Surgery, University of Utah, Salt Lake City, UT, USA
| | - J W Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - G A Zimmerman
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - A S Weyrich
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - M T Rondina
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Internal Medicine, University of Utah, Salt Lake City, UT, USA
- The Geriatric Research Education and Clinical Center (GRECC), University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine at the George E. Wahlen Salt Lake City VAMC, Salt Lake City, Utah, USA
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11
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Jouni R, Zöllner H, Khadour A, Wesche J, Grotevendt A, Brandt S, Delcea M, Krauel K, Schwertz H, Sachs UJ, Greinacher A, Bakchoul T. Partially desulfated heparin modulates the interaction between anti-protamine/heparin antibodies and platelets. Thromb Haemost 2017; 115:324-32. [DOI: 10.1160/th15-07-0539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/24/2015] [Indexed: 11/05/2022]
Abstract
SummaryProtamine (PRT) is the standard drug to neutralise heparin. PRT/heparin complexes induce an immune response similar to that observed in heparin-induced thrombocytopenia (HIT). Partially desulfated heparin (ODSH) was shown to interfere with anti-platelet factor 4/heparin antibodies (Abs), which are responsible for HIT. In this study, we analyse the impact of ODSH on the interaction between anti-PRT/heparin Abs and platelets. The ability of ODSH to prevent anti-PRT/heparin Ab-induced platelet destruction in vivo was investigated using the NOD/ SCID mouse model. ODSH improved platelet survival in the presence of PRT, heparin and anti-PRT/heparin Abs (median platelet survival after 300 minutes (min) with 20 μg/ml ODSH: 75 %, range 70–81 % vs without ODSH: 49%, range 44–59%, p=0.006). Furthermore, when ODSH was applied 60 min after Ab injection platelet survival was improved (median platelet survival after 300 min with ODSH: 83 %, range 77–93 % vs without ODSH: 59 %, range 29–61 %, p=0.02). In in vitro experiments ODSH inhibited platelet activation at concentrations > 16 μg/mL (p< 0.001), as well as PRT/heparin complex binding to platelets (mean fluorescence intensity [MFI] without ODSH: 85 ± 14 vs with ODSH: 15 ± 0.6, p=0.013). ODSH also displaced pre-bound complexes from the platelet surface (MFI without ODSH: 324 ± 43 vs with 32 μg/ml ODSH: 53 ± 9, p< 0.001). While interfering with platelet activation by anti-PRT/heparin Abs, up to a concentration of 16 μg/ml, ODSH had only minimal impact on neutralisation of heparin by PRT. In conclusion, our study shows that ODSH is able to inhibit platelet activation and destruction suggesting a potential clinical use to reduce anti-PRT/heparin Ab-mediated adverse effects.
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12
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Binsker U, Kohler TP, Krauel K, Kohler S, Habermeyer J, Schwertz H, Hammerschmidt S. Serotype 3 pneumococci sequester platelet-derived human thrombospondin-1 via the adhesin and immune evasion protein Hic. J Biol Chem 2017; 292:5770-5783. [PMID: 28209711 DOI: 10.1074/jbc.m116.760504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/15/2017] [Indexed: 11/06/2022] Open
Abstract
Streptococcus pneumoniae serotype 3 strains emerge frequently within clinical isolates of invasive diseases. Bacterial invasion into deeper tissues is associated with colonization and immune evasion mechanisms. Thus, pneumococci express a versatile repertoire of surface proteins sequestering and interacting specifically with components of the human extracellular matrix and serum. Hic, a PspC-like pneumococcal surface protein, possesses vitronectin and factor H binding activity. Here, we show that heterologously expressed Hic domains interact, similar to the classical PspC molecule, with human matricellular thrombospondin-1 (hTSP-1). Binding studies with isolated human thrombospondin-1 and various Hic domains suggest that the interaction between hTSP-1 and Hic differs from binding to vitronectin and factor H. Binding of Hic to hTSP-1 is inhibited by heparin and chondroitin sulfate A, indicating binding to the N-terminal globular domain or type I repeats of hTSP-1. Competitive inhibition experiments with other pneumococcal hTSP-1 adhesins demonstrated that PspC and PspC-like Hic recognize similar domains, whereas PavB and Hic can bind simultaneously to hTSP-1. In conclusion, Hic binds specifically hTSP-1; however, truncation in the N-terminal part of Hic decreases the binding activity, suggesting that the full length of the α-helical regions of Hic is required for an optimal interaction.
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Affiliation(s)
- Ulrike Binsker
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, D-17487 Greifswald, Germany and
| | - Thomas P Kohler
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, D-17487 Greifswald, Germany and
| | - Krystin Krauel
- the Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, D-17489 Greifswald, Germany
| | - Sylvia Kohler
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, D-17487 Greifswald, Germany and
| | - Johanna Habermeyer
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, D-17487 Greifswald, Germany and
| | - Hansjörg Schwertz
- the Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, D-17489 Greifswald, Germany
| | - Sven Hammerschmidt
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, D-17487 Greifswald, Germany and
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13
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Yost CC, Schwertz H, Cody MJ, Wallace JA, Campbell RA, Vieira-de-Abreu A, Araujo CV, Schubert S, Harris ES, Rowley JW, Rondina MT, Fulcher JM, Koening CL, Weyrich AS, Zimmerman GA. Neonatal NET-inhibitory factor and related peptides inhibit neutrophil extracellular trap formation. J Clin Invest 2016; 126:3783-3798. [PMID: 27599294 DOI: 10.1172/jci83873] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 07/28/2016] [Indexed: 12/22/2022] Open
Abstract
Neutrophil granulocytes, also called polymorphonuclear leukocytes (PMNs), extrude molecular lattices of decondensed chromatin studded with histones, granule enzymes, and antimicrobial peptides that are referred to as neutrophil extracellular traps (NETs). NETs capture and contain bacteria, viruses, and other pathogens. Nevertheless, experimental evidence indicates that NETs also cause inflammatory vascular and tissue damage, suggesting that identifying pathways that inhibit NET formation may have therapeutic implications. Here, we determined that neonatal NET-inhibitory factor (nNIF) is an inhibitor of NET formation in umbilical cord blood. In human neonatal and adult neutrophils, nNIF inhibits key terminal events in NET formation, including peptidyl arginine deiminase 4 (PAD4) activity, neutrophil nuclear histone citrullination, and nuclear decondensation. We also identified additional nNIF-related peptides (NRPs) that inhibit NET formation. nNIFs and NRPs blocked NET formation induced by pathogens, microbial toxins, and pharmacologic agonists in vitro and in mouse models of infection and systemic inflammation, and they improved mortality in murine models of systemic inflammation, which are associated with NET-induced collateral tissue injury. The identification of NRPs as neutrophil modulators that selectively interrupt NET generation at critical steps suggests their potential as therapeutic agents. Furthermore, our results indicate that nNIF may be an important regulator of NET formation in fetal and neonatal inflammation.
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Affiliation(s)
- Hansjörg Schwertz
- From the Molecular Medicine Program (H.S., M.T.R.), Departments of Internal Medicine and Surgery (M.T.R.), and Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; and Department of Internal Medicine, George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT (M.T.R.)
| | - Matthew T. Rondina
- From the Molecular Medicine Program (H.S., M.T.R.), Departments of Internal Medicine and Surgery (M.T.R.), and Division of Vascular Surgery (H.S.), University of Utah, Salt Lake City; and Department of Internal Medicine, George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT (M.T.R.)
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15
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Rondina MT, Freitag M, Pluthero FG, Kahr WHA, Rowley JW, Kraiss LW, Franks Z, Zimmerman GA, Weyrich AS, Schwertz H. Non-genomic activities of retinoic acid receptor alpha control actin cytoskeletal events in human platelets. J Thromb Haemost 2016; 14:1082-94. [PMID: 26848712 PMCID: PMC5497578 DOI: 10.1111/jth.13281] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 12/29/2022]
Abstract
UNLABELLED Essentials Platelets employ proteins/signaling pathways traditionally thought reserved for nuclear niche. We determined retinoic-acid-receptor alpha (RARα) expression and function in human platelets. RARα/actin-related protein-2/3 complex (Arp2/3) interact via non-genomic signaling in platelets. RARα regulates Arp2/3-mediated actin cytoskeletal dynamics and platelet spreading. SUMMARY Background Platelets utilize proteins and pathways classically reserved for the nuclear niche. Methods We determined whether human platelets express retinoic-acid-receptor family members, traditionally thought of as nuclear transcription factors, and deciphered the function of RARα. Results We found that RARα is robustly expressed in human platelets and megakaryocytes and interacts directly with actin-related protein-2/3 complex (Arp2/3) subunit 5 (Arp2/3s5). Arp2/3s5 co-localized with RARα in situ and regulated platelet cytoskeletal processes. The RARα ligand all-trans retinoic acid (atRA) disrupted RARα-Arp2/3 interactions. When isolated human platelets were treated with atRA, rapid cytoskeletal events (e.g. platelet spreading) were inhibited. In addition, when platelets were cultured for 18 h in the presence of atRA, actin-dependent morphological changes (e.g. extended cell body formation) were similarly inhibited. Using in vitro actin branching assays, RARα and Arp2/3-regulated complex actin branch formation was demonstrated. Consistent with inhibition of cytoskeletal processes in platelets, atRA, when added to this branching assay, resulted in dysregulated actin branching. Conclusion Our findings identify a previously unknown mechanism by which RARα regulates Arp2/3-mediated actin cytoskeletal dynamics through a non-genomic signaling pathway. These findings have broad implications in both nucleated and anucleate cells, where actin cytoskeletal events regulate cell morphology, movement and division.
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Affiliation(s)
- M T Rondina
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, Salt Lake City, UT, USA
| | - M Freitag
- Department of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - F G Pluthero
- Program in Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | - W H A Kahr
- Program in Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Departments of Paediatrics and Biochemistry, University of Toronto, Toronto, ON, Canada
| | - J W Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - L W Kraiss
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Division of Vascular Surgery, Department of Surgery, University of Utah, Salt Lake City, UT, USA
| | - Z Franks
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - G A Zimmerman
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - A S Weyrich
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - H Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
- Division of Vascular Surgery, Department of Surgery, University of Utah, Salt Lake City, UT, USA
- Lichtenberg-Professor for Experimental Hemostasis, University of Greifswald, Greifswald, Germany
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16
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Krauel K, Schulze A, Jouni R, Hackbarth C, Hietkamp B, Selleng S, Koster A, Jensch I, van der Linde J, Schwertz H, Bakchoul T, Hundt M, Greinacher A. Further insights into the anti-PF4/heparin IgM immune response. Thromb Haemost 2015; 115:752-61. [PMID: 26467272 DOI: 10.1160/th15-08-0654] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/27/2015] [Indexed: 11/05/2022]
Abstract
Anti-platelet factor 4 (PF4)/heparin antibodies are not only the cause of heparin-induced thrombocytopenia but might also play a role in the antibacterial host defence. Recently, marginal zone (MZ) B cells were identified to be crucial for anti-PF4/heparin IgG antibody production in mice. Combining human studies and a murine model of polymicrobial sepsis we further characterised the far less investigated anti-PF4/heparin IgM immune response. We detected anti-PF4/heparin IgM antibodies in the sera of paediatric patients < 6 months of age after cardiac surgery and in sera of splenectomised mice subjected to polymicrobial sepsis. In addition, PF4/heparin-specific IgM B cells were not only found in murine spleen, but also in peritoneum and bone marrow upon in vitro stimulation. Together, this indicates involvement of additional B cell populations, as MZ B cells are not fully developed in humans until the second year of life and are restricted to the spleen in mice. Moreover, PF4/heparin-specific B cells were detected in human cord blood upon in vitro stimulation and PF4-/- mice produced anti-PF4/heparin IgM antibodies after polymicrobial sepsis. In conclusion, the anti-PF4/heparin IgM response is a potential innate immune reaction driven by a B cell population distinct from MZ B cells.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Andreas Greinacher
- Prof. Dr. Andreas Greinacher, Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Strasse, D-17489 Greifswald, Germany, Tel.: +49 3834 865482, Fax: +49 3834 865489, E-mail:
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17
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Berthold T, Glaubitz M, Muschter S, Groß S, Palankar R, Reil A, Helm CA, Bakchoul T, Schwertz H, Bux J, Greinacher A, Delcea M. Human neutrophil antigen-3a antibodies induce neutrophil stiffening and conformational activation of CD11b without shedding of L-selectin. Transfusion 2015; 55:2939-48. [DOI: 10.1111/trf.13299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/27/2015] [Accepted: 06/29/2015] [Indexed: 02/05/2023]
Affiliation(s)
- Tom Berthold
- Institute for Immunology and Transfusion Medicine; Universitätsmedizin Greifswald; Greifswald Germany
| | - Michael Glaubitz
- Nanostructure Group, ZIK HIKE-Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases; Ernst-Moritz-Arndt-University Greifswald; Greifswald Germany
| | - Stefan Muschter
- Institute for Immunology and Transfusion Medicine; Universitätsmedizin Greifswald; Greifswald Germany
| | - Stefan Groß
- Department of Cardiology; Universitätsmedizin Greifswald; Greifswald Germany
- DZHK-German Centre for Cardiovascular Research; Greifswald Germany
| | - Raghavendra Palankar
- Nanostructure Group, ZIK HIKE-Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases; Ernst-Moritz-Arndt-University Greifswald; Greifswald Germany
| | | | | | - Tamam Bakchoul
- Institute for Immunology and Transfusion Medicine; Universitätsmedizin Greifswald; Greifswald Germany
| | - Hansjörg Schwertz
- Institute for Immunology and Transfusion Medicine; Universitätsmedizin Greifswald; Greifswald Germany
- Lichtenberg-Professor for Experimental Hemostasis; Universitätsmedizin Greifswald
- Program in Molecular Medicine; University of Utah; Salt Lake City Utah
- Department of Surgery; University of Utah; Salt Lake City Utah
| | | | - Andreas Greinacher
- Institute for Immunology and Transfusion Medicine; Universitätsmedizin Greifswald; Greifswald Germany
| | - Mihaela Delcea
- Nanostructure Group, ZIK HIKE-Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases; Ernst-Moritz-Arndt-University Greifswald; Greifswald Germany
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18
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Binsker U, Kohler TP, Krauel K, Kohler S, Schwertz H, Hammerschmidt S. Pneumococcal Adhesins PavB and PspC Are Important for the Interplay with Human Thrombospondin-1. J Biol Chem 2015; 290:14542-55. [PMID: 25897078 DOI: 10.1074/jbc.m114.623876] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Indexed: 11/06/2022] Open
Abstract
The human matricellular glycoprotein thrombospondin-1 (hTSP-1) is released by activated platelets and mediates adhesion of Gram-positive bacteria to various host cells. In staphylococci, the adhesins extracellular adherence protein (Eap) and autolysin (Atl), both surface-exposed proteins containing repeating structures, were shown to be involved in the acquisition of hTSP-1 to the bacterial surface. The interaction partner(s) on the pneumococcal surface was hitherto unknown. Here, we demonstrate for the first time that pneumococcal adherence and virulence factor B (PavB) and pneumococcal surface protein C (PspC) are key players for the interaction of Streptococcus pneumoniae with matricellular hTSP-1. PavB and PspC are pneumococcal surface-exposed adhesins and virulence factors exhibiting repetitive sequences in their core structure. Heterologously expressed fragments of PavB and PspC containing repetitive structures exhibit hTSP-1 binding activity as shown by ELISA and surface plasmon resonance studies. Binding of hTSP-1 is charge-dependent and inhibited by heparin. Importantly, the deficiency in PavB and PspC reduces the recruitment of soluble hTSP-1 by pneumococci and decreases hTSP-1-mediated pneumococcal adherence to human epithelial cells. Platelet activation assays suggested that PavB and PspC are not involved in the activation of purified human platelets by pneumococci. In conclusion, this study indicates a pivotal role of PavB and PspC for pneumococcal recruitment of soluble hTSP-1 to the bacterial surface and binding of pneumococci to host cell-bound hTSP-1 during adhesion.
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Affiliation(s)
- Ulrike Binsker
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany and
| | - Thomas P Kohler
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany and
| | - Krystin Krauel
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse, D-17489 Greifswald, Germany
| | - Sylvia Kohler
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany and
| | - Hansjörg Schwertz
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse, D-17489 Greifswald, Germany
| | - Sven Hammerschmidt
- From the Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany and
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19
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Shi DS, Smith MCP, Campbell RA, Zimmerman PW, Franks ZB, Kraemer BF, Machlus KR, Ling J, Kamba P, Schwertz H, Rowley JW, Miles RR, Liu ZJ, Sola-Visner M, Italiano JE, Christensen H, Kahr WHA, Li DY, Weyrich AS. Proteasome function is required for platelet production. J Clin Invest 2014; 124:3757-66. [PMID: 25061876 DOI: 10.1172/jci75247] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 06/05/2014] [Indexed: 01/03/2023] Open
Abstract
The proteasome inhibiter bortezomib has been successfully used to treat patients with relapsed multiple myeloma; however, many of these patients become thrombocytopenic, and it is not clear how the proteasome influences platelet production. Here we determined that pharmacologic inhibition of proteasome activity blocks proplatelet formation in human and mouse megakaryocytes. We also found that megakaryocytes isolated from mice deficient for PSMC1, an essential subunit of the 26S proteasome, fail to produce proplatelets. Consistent with decreased proplatelet formation, mice lacking PSMC1 in platelets (Psmc1(fl/fl) Pf4-Cre mice) exhibited severe thrombocytopenia and died shortly after birth. The failure to produce proplatelets in proteasome-inhibited megakaryocytes was due to upregulation and hyperactivation of the small GTPase, RhoA, rather than NF-κB, as has been previously suggested. Inhibition of RhoA or its downstream target, Rho-associated protein kinase (ROCK), restored megakaryocyte proplatelet formation in the setting of proteasome inhibition in vitro. Similarly, fasudil, a ROCK inhibitor used clinically to treat cerebral vasospasm, restored platelet counts in adult mice that were made thrombocytopenic by tamoxifen-induced suppression of proteasome activity in megakaryocytes and platelets (Psmc1(fl/fl) Pdgf-Cre-ER mice). These results indicate that proteasome function is critical for thrombopoiesis, and suggest inhibition of RhoA signaling as a potential strategy to treat thrombocytopenia in bortezomib-treated multiple myeloma patients.
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Schmid DI, Schwertz H, Jiang H, Campbell RA, Weyrich AS, McIntyre TM, Zimmerman GA, Kraiss LW. Translational control of JunB, an AP-1 transcription factor, in activated human endothelial cells. J Cell Biochem 2013; 114:1519-28. [PMID: 23297064 DOI: 10.1002/jcb.24493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 12/18/2012] [Indexed: 12/31/2022]
Abstract
Stimulated endothelial cells (EC) assume an activated phenotype with pro-inflammatory and prothrombotic features, requiring new gene and protein expression. New protein synthesis in activated EC is largely regulated by transcriptional events controlled by a variety of transcription factors. However, post-transcriptional control of gene expression also influences phenotype and allows the cell to alter protein expression in a faster and more direct way than is typically possible with transcriptional mechanisms. We sought to demonstrate that post-transcriptional control of gene expression occurs during EC activation. Using thrombin-activated EC and a high-throughput, microarray-based approach, we identified a number of gene products that may be regulated through post-transcriptional mechanisms, including the AP-1 transcription factor JunB. Using polysome profiling, cytoplasts and other standard cell biologic techniques, JunB is shown to be regulated at a post-transcriptional level during EC activation. In activated EC, the AP-1 transcription factor JunB, is regulated on a post-transcriptional level. Signal-dependent control of translation may regulate transcription factor expression and therefore, subsequent transcriptional events in stimulated EC.
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Affiliation(s)
- Douglas I Schmid
- Division of Vascular Surgery, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA
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Andrews RK, Aster RH, Atkinson BT, Barnard MR, Bavry AA, Bayer AS, Beaulieu LM, Berndt MC, Berny-Lang MA, Bhatt DL, Bizzaro N, Bledzka K, Bouchard BA, Brass LF, Bray PF, Briggs C, Bussel JB, Cattaneo M, Chakravorty S, Chong BH, Clemetson J, Clemetson KJ, Coller BS, Covic L, Davì G, del Zoppo GJ, Dowling MR, Dubois C, Eisert WG, Evangelista V, Flaumenhaft R, Freedman JE, Freedman J, Frelinger AL, Furie BC, Furie B, Gardiner C, Gawaz M, Geisler T, Greinacher A, Gurbel PA, Harrison P, Hartwig JH, Hayward CP, Hughes CE, Ikeda Y, Israels SJ, Italiano JE, Jackson S, Jain S, Jones CI, Josefsson EC, Kaplan C, Kile BT, Kimura Y, Klement GL, Kolandaivelu K, Kuliopulos A, Kuter DJ, Lambert MP, Langer HF, Lebois M, Levin J, Lordkipanidzé M, Ma YQ, Mannucci PM, McCrae KR, Merrill-Skoloff G, Michelson AD, Moffat KA, Mutch NJ, Newman DK, Newman PE, Ni H, Nieuwland R, Ouwehand WH, Parsons J, Patrono C, Perrotta PL, Pesho MM, Plow EF, Politt AY, Poncz M, Poon MC, Provost P, Psaila B, Rao AK, Rinder HM, Roberts IA, Rondina MT, Ruggeri ZM, Santilli F, Schwertz H, Shai E, Silveira JR, Smith BR, Smith MC, Smyth SS, Snyder EL, Sobel M, Soranzo N, Stalker TJ, Sturk A, Sudo T, Sullivan S, Tantry US, Tefferi A, Tracy PB, Tsai HM, van der Pol E, Varon D, Vazzana N, Vieira-de-Abreu A, Wannemacher K, Ware J, Warkentin TE, Watson SP, Weyrich AS, White JG, Wilcox DA, Yeaman MR, Zhang P, Zhu L, Zimmerman GA. List of Contributors. Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00072-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
PURPOSE OF REVIEW It is now well appreciated that megakaryocytes invest platelets with a diverse repertoire of messenger RNAs (mRNAs), which are competent for translation. Herein we describe what is currently known regarding the expression, function, and clinical significance of mRNAs in platelets. RECENT FINDINGS Although mRNA was detected in platelets nearly 30 years ago, we are only beginning to understand the roles of mRNA in platelet biology and human disease. Recent studies have shown that megakaryocytes specifically sort, rather than randomly transfer, mRNA to platelets during thrombopoiesis. As a result, platelets are released into the circulation with thousands of mRNAs. The emergence of next-generation RNA sequencing has demonstrated that platelet mRNAs possess classic structural features, which include untranslated regions and open reading frames. There is also growing evidence that platelet mRNA expression patterns are altered in human disease. SUMMARY Intense investigation of platelet mRNA has shed considerable light on predicted functions of platelets and identified previously unrecognized attributes of platelets. Lessons learned from platelet mRNA is presented in this review.
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Affiliation(s)
- Jesse W Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, USA
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Jiang H, Schwertz H, Schmid DI, Jones BB, Kriesel J, Martinez ML, Weyrich AS, Zimmerman GA, Kraiss LW. Different mechanisms preserve translation of programmed cell death 8 and JunB in virus-infected endothelial cells. Arterioscler Thromb Vasc Biol 2012; 32:997-1004. [PMID: 22328780 DOI: 10.1161/atvbaha.112.245324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Translation initiation of eukaryotic mRNAs typically occurs by cap-dependent ribosome scanning mechanism. However, certain mRNAs are translated by ribosome assembly at internal ribosome entry sites (IRESs). Whether IRES-mediated translation occurs in stressed primary human endothelial cells (ECs) is unknown. METHODS AND RESULTS We performed microarray analysis of polyribosomal mRNA from ECs to identify IRES-containing mRNAs. Cap-dependent translation was disabled by poliovirus (PV) infection and confirmed by loss of polysome peaks, detection of eukaryotic initiation factor (eIF) 4G cleavage, and decreased protein synthesis. We found that 87.4% of mRNAs were dissociated from polysomes in virus-infected ECs. Twelve percent of mRNAs remained associated with polysomes, and 0.6% were enriched ≥2-fold in polysome fractions from infected ECs. Quantitative reverse transcription-polymerase chain reaction confirmed the microarray findings for 31 selected mRNAs. We found that enriched polysome associations of programmed cell death 8 (PDCD8) and JunB mRNA resulted in increased protein expression in PV-infected ECs. The presence of IRESs in the 5' untranslated region of PDCD8 mRNA, but not of JunB mRNA, was confirmed by dicistronic analysis. CONCLUSIONS We show that microarray profiling of polyribosomal mRNA transcripts from PV-infected ECs successfully identifies mRNAs whose translation is preserved in the face of stress-induced, near complete cessation of cap-dependent initiation. Nevertheless, internal ribosome entry is not the only mechanism responsible for this privileged translation.
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Affiliation(s)
- Huimiao Jiang
- Division of Vascular Surgery, University of Utah, Salt Lake City, USA
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Abstract
Platelets are anucleate cytoplasts that circulate in the bloodstream for approximately 9-11 days. Because they lack nuclei, platelets were considered incapable of protein synthesis. However, studies over the last decade have revealed that platelets use a variety of translational control pathways to synthesize proteins.A variety of protocols can be employed to assess protein synthesis by platelets. These protocols are scattered throughout the literature and, more often than not, lack critical details. In this chapter, we thoroughly outline methods used in our laboratory to assess protein synthesis by platelets.
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Affiliation(s)
- Hansjörg Schwertz
- Program in Molecular Medicine, Department of Surgery, University of Utah, Salt Lake City, UT, USA
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Kraemer BF, Campbell RA, Schwertz H, Cody MJ, Franks Z, Tolley ND, Kahr WHA, Lindemann S, Seizer P, Yost CC, Zimmerman GA, Weyrich AS. Novel anti-bacterial activities of β-defensin 1 in human platelets: suppression of pathogen growth and signaling of neutrophil extracellular trap formation. PLoS Pathog 2011; 7:e1002355. [PMID: 22102811 PMCID: PMC3213094 DOI: 10.1371/journal.ppat.1002355] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/20/2011] [Indexed: 12/11/2022] Open
Abstract
Human β-defensins (hBD) are antimicrobial peptides that curb microbial activity. Although hBD's are primarily expressed by epithelial cells, we show that human platelets express hBD-1 that has both predicted and novel antibacterial activities. We observed that activated platelets surround Staphylococcus aureus (S. aureus), forcing the pathogens into clusters that have a reduced growth rate compared to S. aureus alone. Given the microbicidal activity of β-defensins, we determined whether hBD family members were present in platelets and found mRNA and protein for hBD-1. We also established that hBD-1 protein resided in extragranular cytoplasmic compartments of platelets. Consistent with this localization pattern, agonists that elicit granular secretion by platelets did not readily induce hBD-1 release. Nevertheless, platelets released hBD-1 when they were stimulated by α-toxin, a S. aureus product that permeabilizes target cells. Platelet-derived hBD-1 significantly impaired the growth of clinical strains of S. aureus. hBD-1 also induced robust neutrophil extracellular trap (NET) formation by target polymorphonuclear leukocytes (PMNs), which is a novel antimicrobial function of β-defensins that was not previously identified. Taken together, these data demonstrate that hBD-1 is a previously-unrecognized component of platelets that displays classic antimicrobial activity and, in addition, signals PMNs to extrude DNA lattices that capture and kill bacteria. Platelets are small cells in the bloodstream whose primary function is to stop bleeding. In addition to their clotting functions, we show that human platelets stall bacterial growth. This inhibitory property of platelets is due to β-defensin 1, a small antimicrobial protein that kills bacteria. β-defensin 1 also induces white blood cells to discharge spider-like webs that trap and kill bacteria. Together, these findings indicate that human platelets use β-defensin 1 to fight off bacterial infection.
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Affiliation(s)
- Bjoern F. Kraemer
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
- Medizinische Klinik III, Universitaetsklinikum Tuebingen, Tuebingen, Germany
| | - Robert A. Campbell
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Hansjörg Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
- Department of Surgery, University of Utah, Salt Lake City, Utah, United States of America
| | - Mark J. Cody
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Zechariah Franks
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Neal D. Tolley
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Walter H. A. Kahr
- Division of Haematology/Oncology, Program in Cell Biology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | | | - Peter Seizer
- Medizinische Klinik III, Universitaetsklinikum Tuebingen, Tuebingen, Germany
| | - Christian C. Yost
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Guy A. Zimmerman
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Andrew S. Weyrich
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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Kahr WHA, Hinckley J, Li L, Schwertz H, Christensen H, Rowley JW, Pluthero FG, Urban D, Fabbro S, Nixon B, Gadzinski R, Storck M, Wang K, Ryu GY, Jobe SM, Schutte BC, Moseley J, Loughran NB, Parkinson J, Weyrich AS, Di Paola J. Mutations in NBEAL2, encoding a BEACH protein, cause gray platelet syndrome. Nat Genet 2011; 43:738-40. [PMID: 21765413 PMCID: PMC6050511 DOI: 10.1038/ng.884] [Citation(s) in RCA: 179] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 06/15/2011] [Indexed: 11/09/2022]
Abstract
Next-generation RNA sequence analysis of platelets from an individual with autosomal recessive gray platelet syndrome (GPS, MIM139090) detected abnormal transcript reads, including intron retention, mapping to NBEAL2 (encoding neurobeachin-like 2). Genomic DNA sequencing confirmed mutations in NBEAL2 as the genetic cause of GPS. NBEAL2 encodes a protein containing a BEACH domain that is predicted to be involved in vesicular trafficking and may be critical for the development of platelet α-granules.
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Affiliation(s)
- Walter H A Kahr
- Department of Paediatrics, University of Toronto, Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, Ontario, Canada.
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Rondina MT, Schwertz H, Harris ES, Kraemer BF, Campbell RA, Mackman N, Grissom CK, Weyrich AS, Zimmerman GA. The septic milieu triggers expression of spliced tissue factor mRNA in human platelets. J Thromb Haemost 2011; 9:748-58. [PMID: 21255247 PMCID: PMC3071458 DOI: 10.1111/j.1538-7836.2011.04208.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Activated platelets have previously-unrecognized mechanisms of post-transcriptional gene expression that may influence hemostasis and inflammation. A novel pathway involves splicing of pre-mRNAs in resting platelets to mature, translatable mRNAs in response to cellular activation. OBJECTIVES We asked if bacterial products and host agonists present in the septic milieu induce tissue factor pre-mRNA splicing in platelets from healthy subjects. In parallel, we asked if spliced tissue factor (TF) mRNA is present in platelets from septic patients in a proof-of-principle analysis. PATIENTS/METHODS TF pre-mRNA and mRNA expression patterns were characterized in platelets from septic patients and in platelets isolated from healthy subjects activated with bacteria, toxins and inflammatory agonists. Procoagulant activity was also measured. RESULTS AND CONCLUSIONS Live bacteria, staphylococcal α-toxin and lipopolysaccharide (LPS) induced TF pre-mRNA splicing in platelets isolated from healthy subjects. Toxin-stimulated platelets accelerated plasma clotting, a response that was blocked by a previously-characterized splicing inhibitor and by an anti-tissue factor antibody. Platelets from septic patients expressed spliced TF mRNA, whereas it was absent from unselected and age-matched control subjects. Tissue factor-dependent procoagulant activity was elevated in platelets from a subset of septic patients. Thus, bacterial and host factors induce splicing of TF pre-mRNA, expression of TF mRNA and tissue factor-dependent clotting activity in human platelets. TF mRNA is present in platelets from some septic patients, indicating that it may be a marker of altered platelet phenotype and function in sepsis and that splicing pathways are induced in this syndrome.
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Affiliation(s)
- M T Rondina
- Division of General Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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Schubert S, Schwertz H, Weyrich AS, Franks ZG, Lindemann S, Otto M, Behr H, Loppnow H, Schlitt A, Russ M, Presek P, Werdan K, Buerke M. Staphylococcus aureus α-toxin triggers the synthesis of B-cell lymphoma 3 by human platelets. Toxins (Basel) 2011; 3:120-33. [PMID: 22069700 PMCID: PMC3202813 DOI: 10.3390/toxins3020120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 01/22/2011] [Accepted: 01/25/2011] [Indexed: 01/20/2023] Open
Abstract
The frequency and severity of bacteremic infections has increased over the last decade and bacterial endovascular infections (i.e., sepsis or endocarditis) are associated with high morbidity and mortality. Bacteria or secreted bacterial products modulate platelet function and, as a result, affect platelet accumulation at sites of vascular infection and inflammation. However, whether bacterial products regulate synthetic events in platelets is not known. In the present study, we determined if prolonged contact with staphylococcal α-toxin signals platelets to synthesize B-cell lymphoma (Bcl-3), a protein that regulates clot retraction in murine and human platelets. We show that α-toxin induced α(IIb)β(3)-dependent aggregation (EC(50) 2.98 µg/mL ± 0.64 µg/mL) and, over time, significantly altered platelet morphology and stimulated de novo accumulation of Bcl-3 protein in platelets. Adherence to collagen or fibrinogen also increased the expression of Bcl-3 protein by platelets. α-toxin altered Bcl-3 protein expression patterns in platelets adherent to collagen, but not fibrinogen. Pretreatment of platelets with inhibitors of protein synthesis or the mammalian Target of Rapamycin (mTOR) decreased Bcl-3 protein expression in α-toxin stimulated platelets. In conclusion, Staphylococcusaureus-derived α-toxin, a pore forming exotoxin, exerts immediate (i.e., aggregation) and prolonged (i.e., protein synthesis) responses in platelets, which may contribute to increased thrombotic events associated with gram-positive sepsis or endocarditis.
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Affiliation(s)
- Sebastian Schubert
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Hansjörg Schwertz
- Program in Molecular Medicine, University of Utah, Salt Lake City, UT 84112, USA; (H.S.); (A.S.W.); (Z.G.F.)
| | - Andrew S. Weyrich
- Program in Molecular Medicine, University of Utah, Salt Lake City, UT 84112, USA; (H.S.); (A.S.W.); (Z.G.F.)
| | - Zechariah G. Franks
- Program in Molecular Medicine, University of Utah, Salt Lake City, UT 84112, USA; (H.S.); (A.S.W.); (Z.G.F.)
| | - Stephan Lindemann
- Department of Medicine III, Eberhard Karls University, Tübingen, Germany;
| | - Monika Otto
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Hagen Behr
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Harald Loppnow
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Axel Schlitt
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Martin Russ
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Peter Presek
- Clinical Pharmacology, Martin Luther University, Halle, Saale, Germany;
| | - Karl Werdan
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
| | - Michael Buerke
- Department of Medicine III, Martin Luther University, Halle, Saale, Germany; (S.S.); (M.O.); (H.B.); (H.L.); (A.S.); (M.R.); (K.W.)
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Abstract
In this issue, Thon et al. (2010. J. Cell Biol. doi: 10.1083/jcb.201006102) demonstrate that newly released platelets exhibit bipolar behavior, shifting back and forth between round cells and multibodied proplatelets (Thon et al., 2010). The authors define this intermediate as a preplatelet and, in doing so, shed new insight into the terminal steps of platelet maturation.
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Affiliation(s)
- Hansjörg Schwertz
- Program in Molecular Medicine, University of Utah, Salt Lake City, UT 84112, USA
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Niessen J, Jedlitschky G, Grube M, Bien S, Schwertz H, Ohtsuki S, Kawakami H, Kamiie J, Oswald S, Starke K, Strobel U, Siegmund W, Rosskopf D, Greinacher A, Terasaki T, Kroemer HK. Human platelets express organic anion-transporting peptide 2B1, an uptake transporter for atorvastatin. Drug Metab Dispos 2009; 37:1129-37. [PMID: 19237515 DOI: 10.1124/dmd.108.024570] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Statins are widely used to treat dyslipidemia. Effects of statins in addition to low-density lipoprotein lowering include altered platelet aggregation, requiring drug uptake into platelets. Possible candidates for mediating intraplatelet accumulation of statins include members of the organic anion-transporting polypeptide family such as OATP2B1 (SLCO2B1), a high-affinity uptake transporter for atorvastatin. Therefore, we analyzed OATP expression, localization, and function in human platelets. OATP2B1, but not OATP1B1, was detected in platelets and megakaryocytes on transcript and protein levels. Protein localization was almost exclusively confined to the plasma membrane. Moreover, we could demonstrate significant inhibition of estrone sulfate uptake into platelets by atorvastatin as well as direct transport of atorvastatin into platelets using a liquid chromatography-tandem mass spectrometry method. As a consequence of OATP2B1-mediated uptake of atorvastatin, we observed significant atorvastatin-mediated reduction of thrombin-induced Ca(2+) mobilization in platelets (37.3 +/- 6.7% of control at 15 microM atorvastatin), mechanistically explainable by reduced lipid modification of signal proteins. This effect was reversed by addition of mevalonate. Finally, we demonstrated expression of HMG-CoA reductase, the primary target of atorvastatin, in platelet cytosol. In conclusion, OATP2B1 is an uptake transporter expressed in platelets and is involved in statin-mediated alteration of platelet aggregation.
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Affiliation(s)
- Juliane Niessen
- Department of Pharmacology, Research Center of Pharmacology and Experimental Therapeutics, Ernst-Moritz-Arndt-University, Friedrich-Loeffler-Str. 23 D, D-17487 Greifswald, Germany
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Abstract
In the late 1960s, numerous investigators independently demonstrated that platelets are capable of synthesizing proteins. Studies continued at a steady pace over the next 30 years and into the 21st century. Collectively, these investigations confirmed that platelets synthesize proteins and that the pattern of protein synthesis changes in response to cellular activation. More recent studies have characterized the mechanisms by which platelets synthesize proteins and have shown that protein synthesis alters the phenotype and functions of platelets. Here, we chronologically review our increased understanding of protein synthetic responses in platelets and discuss how the field may evolve over the next decade.
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Affiliation(s)
- A S Weyrich
- Department of Internal Medicine, University of Utah, Salt Lake City, UT 84112, USA.
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Schwertz H, Carter JM, Abdudureheman M, Russ M, Buerke U, Schlitt A, Müller-Werdan U, Prondzinsky R, Werdan K, Buerke M. Myocardial ischemia/reperfusion causes VDAC phosphorylation which is reduced by cardioprotection with a p38 MAP kinase inhibitor. Proteomics 2008; 7:4579-88. [PMID: 18072194 DOI: 10.1002/pmic.200700734] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Myocardial ischemia (MI) and reperfusion (R) results in activation of the p38 MAP kinase pathway. This pathway phosphorylates transcription factors and cytoplasmic proteins leading to expression of adhesion molecules and cytokines, increased neutrophil activation, and finally, myocardial necrosis and apoptosis. We studied the effects of a p38 MAP kinase inhibitor, PD169316, on cardioprotection, protein expression, and tyrosine phosphorylation, in a rabbit model of 1 h of (MI) and 3 h of (R). PD169316 administered just before (R) significantly reduced myocardial neutrophil accumulation, necrosis area (28.4 +/- 7.9% vs. 56.4 +/- 7.9% necrosis/AAR), and CK release compared to a vehicle treated group (p<0.05). We found several proteins altered in expression following MI + R alone or with p38 inhibition including myofilament proteins, energetics proteins, heat shock proteins, and the mitochondrial porin VDAC-1. p38 MAPK inhibition significantly reduced the phosphorylation of VDAC-1 which is a known mitochondrial regulator of cell survival. Thus, p38 MAP kinase inhibition with PD169316 is cardioprotective, reduces neutrophil activation, and controls protein expression and phosphorylation in MI and reperfusion.
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Affiliation(s)
- Hansjörg Schwertz
- Department of Internal Medicine III, Martin-Luther-University, Halle-Wittenberg, Halle/Saale, Germany
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Schwertz H, Tolley ND, Foulks JM, Denis MM, Risenmay BW, Buerke M, Tilley RE, Rondina MT, Harris EM, Kraiss LW, Mackman N, Zimmerman GA, Weyrich AS. Signal-dependent splicing of tissue factor pre-mRNA modulates the thrombogenicity of human platelets. ACTA ACUST UNITED AC 2006; 203:2433-40. [PMID: 17060476 PMCID: PMC2118136 DOI: 10.1084/jem.20061302] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Tissue factor (TF) is an essential cofactor for the activation of blood coagulation in vivo. We now report that quiescent human platelets express TF pre-mRNA and, in response to activation, splice this intronic-rich message into mature mRNA. Splicing of TF pre-mRNA is associated with increased TF protein expression, procoagulant activity, and accelerated formation of clots. Pre-mRNA splicing is controlled by Cdc2-like kinase (Clk)1, and interruption of Clk1 signaling prevents TF from accumulating in activated platelets. Elevated intravascular TF has been reported in a variety of prothrombotic diseases, but there is debate as to whether anucleate platelets-the key cellular effector of thrombosis-express TF. Our studies demonstrate that human platelets use Clk1-dependent splicing pathways to generate TF protein in response to cellular activation. We propose that platelet-derived TF contributes to the propagation and stabilization of a thrombus.
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Affiliation(s)
- Hansjörg Schwertz
- Department of Internal Medicine, University of Utah, Salt Lake City, UT 84112, USA
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35
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Buerke M, Guckenbiehl M, Schwertz H, Buerke U, Hilker M, Platsch H, Richert J, Bomm S, Zimmerman GA, Lindemann S, Mueller-Werdan U, Werdan K, Darius H, Weyrich AS. Intramural delivery of Sirolimus prevents vascular remodeling following balloon injury. Biochim Biophys Acta 2006; 1774:5-15. [PMID: 16920414 PMCID: PMC2275912 DOI: 10.1016/j.bbapap.2006.04.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 04/04/2006] [Accepted: 04/24/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Several studies have demonstrated that Sirolimus-eluting stents reduce restenosis in patients with coronary artery disease. Here, we tested whether direct delivery of Sirolimus into the vessel wall during balloon angioplasty can modify vascular remodeling over several weeks. METHODS AND RESULTS During angioplasty of the rabbit iliac artery we administered an intramural infusion of Sirolimus or its vehicle directly through a balloon catheter into the vessel wall. After 3 weeks neointimal formation was decreased (0.71+/-0.1 vs. 1.4+/-0.12 intima/media ratio), and this process was attributed to the inhibitory properties of Sirolimus on ECM deposition and smooth muscle cell proliferation. Sirolimus also significantly reduced the deposition of elastin, collagen III and fibronectin within the vascular wall. In parallel, proteomic profiles of arterial wall segments were obtained and 485 protein spots were consistently matched between non-dilated and dilated vessels. Differential expression of 12 proteins were observed between the groups and direct sequencing of digested peptides was performed. Local delivery of sirolimus during angioplasty attenuated the expression of structural proteins that included lamin A, vimentin, alpha-1-antitrypsin, and alpha-actin. CONCLUSIONS Local administration of Sirolimus during angioplasty prevents smooth muscle cell proliferation associated with vascular remodeling as well as the expression of extracellular matrix and structural proteins. Therefore, local injection of Sirolimus during balloon inflation may be an alternative therapeutic approach for preventing restenosis in small stenotic vessels (i.e., <2.5 mm).
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Affiliation(s)
- Michael Buerke
- Department of Medicine III, Martin-Luther-University, Ernst-Grube-Str. 40, 06097 Halle, and Department of Cardiology, Neu-Kölln-Hospital, Berlin, Germany.
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36
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Buerke M, Schwertz H, Längin T, Buerke U, Prondzinsky R, Platsch H, Richert J, Bomm S, Schmidt M, Hillen H, Lindemann S, Blaschke G, Müller-Werdan U, Werdan K. Proteome analysis of myocardial tissue following ischemia and reperfusion--effects of complement inhibition. Biochim Biophys Acta 2006; 1764:1536-45. [PMID: 17045855 DOI: 10.1016/j.bbapap.2006.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Accepted: 03/04/2006] [Indexed: 10/24/2022]
Abstract
Myocardial ischemia-reperfusion injury can be related to complement activation with generation of chemotactic mediators, release of cytokines, leukocyte accumulation, and subsequent severe tissue injury. In this regard, activation of transcription factors (i.e., NFkappaB) and de novo protein synthesis or inflammatory protein degradation seems to play an important role. In the present study, we analyzed the cardiac protein expression following myocardial ischemia (60 min) and reperfusion (180 min) in a rabbit model utilizing two-dimensional electrophoresis and nanoHPLC/ESI-MS/MS for biochemical protein identification. To achieve cardioprotective effects, we used a novel highly selective small molecule C1s inhibitor administered 5 min prior to reperfusion. The reduction of myocardial injury was observed as diminished plasma creatine kinase activity in C1s-INH-248-treated animals (65.2+/-3 vs. 38.5+/-3 U/g protein after 3 h of reperfusion, P<0.05). With proteome analysis we were able to detect 509+/-21 protein spots on the gels of the 3 groups. A pattern of 480 spots with identical positions was found on every gel of myocardial tissue of sham animals, vehicle and C1s-INH-248-treated animals. We analyzed 11 spots, which were identified by mass spectrometry: Superoxide dismutase, alpha-crystallin-chain-B, mitochondrial stress protein, Mn SOD, ATP synthase A chain heart isoform, creatine kinase, and troponin T. All of these proteins were significantly decreased in the vehicle group when we compared to sham-treated animals. Treatment with C1s-INH-248 preserved levels of these proteins. Thus, blocking the classical complement pathway with a highly specific and potent synthetic inhibitor of the activated C1 complex archives cardio-protection by altering and preserving different anti-inflammatory and cytoprotective cascades.
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Affiliation(s)
- Michael Buerke
- Department of Medicine III, Martin-Luther-University, Ernst-Grube-Str. 40, 06097 Halle, Germany.
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37
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Denis MM, Tolley ND, Bunting M, Schwertz H, Jiang H, Lindemann S, Yost CC, Rubner FJ, Albertine KH, Swoboda KJ, Fratto CM, Tolley E, Kraiss LW, McIntyre TM, Zimmerman GA, Weyrich AS. Escaping the nuclear confines: signal-dependent pre-mRNA splicing in anucleate platelets. Cell 2005; 122:379-91. [PMID: 16096058 PMCID: PMC4401993 DOI: 10.1016/j.cell.2005.06.015] [Citation(s) in RCA: 487] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 04/19/2005] [Accepted: 06/07/2005] [Indexed: 02/02/2023]
Abstract
Platelets are specialized hemostatic cells that circulate in the blood as anucleate cytoplasts. We report that platelets unexpectedly possess a functional spliceosome, a complex that processes pre-mRNAs in the nuclei of other cell types. Spliceosome components are present in the cytoplasm of human megakaryocytes and in proplatelets that extend from megakaryocytes. Primary human platelets also contain essential spliceosome factors including small nuclear RNAs, splicing proteins, and endogenous pre-mRNAs. In response to integrin engagement and surface receptor activation, platelets precisely excise introns from interleukin-1beta pre-mRNA, yielding a mature message that is translated into protein. Signal-dependent splicing is a novel function of platelets that demonstrates remarkable specialization in the regulatory repertoire of this anucleate cell. While this mechanism may be unique to platelets, it also suggests previously unrecognized diversity regarding the functional roles of the spliceosome in eukaryotic cells.
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Affiliation(s)
- Melvin M. Denis
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Neal D. Tolley
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Michaeline Bunting
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Hansjörg Schwertz
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Huimiao Jiang
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Stephan Lindemann
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Christian C. Yost
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Pediatrics, University of Utah, Salt Lake City, Utah 84112
| | - Frederick J. Rubner
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Pediatrics, University of Utah, Salt Lake City, Utah 84112
| | - Kurt H. Albertine
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84112
- Department of Pediatrics, University of Utah, Salt Lake City, Utah 84112
| | - Kathryn J. Swoboda
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Neurology, University of Utah, Salt Lake City, Utah 84112
- Department of Pediatrics, University of Utah, Salt Lake City, Utah 84112
| | - Carolyn M. Fratto
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Emilysa Tolley
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Larry W. Kraiss
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | | | - Guy A. Zimmerman
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84112
| | - Andrew S. Weyrich
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah 84112
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84112
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Schwertz H, Prondzinsky R, Hofmann HS, Silber RE, Werdan K, Buerke M. Transesophageal echocardiographic image of a thrombus crossing a persistent foramen ovale from the right into the left atrium. J Am Soc Echocardiogr 2005; 18:278-9. [PMID: 15746721 DOI: 10.1016/j.echo.2004.10.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Hansjörg Schwertz
- Dpartment of Medicine III, Cardiology, Angiology, Intensive Care Medicine, Martin-Luther University, Ernst-Grube-Strasse 40, 06097 Halle/Saale, Germany
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Schwertz H, Müller-Werdan U, Prondzinsky R, Werdan K, Buerke M. Katecholamine im kardiogenen Schock: hilfreich, nutzlos oder gefährlich? Dtsch Med Wochenschr 2004; 129:1925-30. [PMID: 15372372 DOI: 10.1055/s-2004-831364] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Cardiogenic shock is characterized by inadequate organ and tissue perfusion, due to cardiac dysfunction, predominantly following acute myocardial infarction. Mortality rates for patients with cardiogenic shock remain high, ranging from 50-70 % despite effective therapy. Rapid diagnostics, aggressive therapeutic approach (invasive or surgical revascularisation) and pharmacological support are currently used to improve the clinical outcome and survival. In the first line commonly sympathomimetics like dopamine, dobutamine, epinephrine and norepinephrine are used for the pharmacological treatment. They have a high affinity for alpha- and beta adrenergic receptors, leading to a positive inotropic cardiac function, an increase in heart rate, oxygen enhanced demand, and an increase in vasoconstriction. However, there are also some disadvantages in the use of sympathomimetics in patients with cardiogenic shock. Clearly, metabolic acidosis due to the increased oxygen demand can be observed. Vasoconstriction induced by sympathomimetics can lead to perfusion mismatch or even deficit within the microcirculation. Additionally, in some studies which give evidence that the use of sympathomimetics can directly lead to enhanced systemic inflammatory response due to an increased IL-6 expression. However, sympathomimetics are still first line therapeutics for treatment of cardiogenic shock -- with respect to dosage and duration of treatment.
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Affiliation(s)
- H Schwertz
- Medizinische Universitätsklinik und Poliklinik III, Klinikum der Medizinischen Fakultät, Martin Luther-Universität Halle-Wittenberg, Halle/Saale
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40
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Abstract
BACKGROUND Proliferation and migration of vascular smooth muscle cells (SMCs) mark the key processes in the development of bypass graft disease and during neointima formation in restenosis after angioplasty. Growth factors are potent SMC mitogens as they are involved in SMC proliferation and in extracellular matrix (ECM) synthesis. Based on these premises, we examined the effect of the proliferation inhibitor rapamycin in human SMC culture and in a rabbit vascular injury model. MATERIALS AND METHODS Injection of rapamycin or its vehicle was performed with an infusion-balloon catheter directly into the vessel wall during vascular injury. The intima/media ratio was determined histologically whereas the protein expression was analysed using the powerful two-dimensional gel electrophoresis (2D page) technique. Inhibition of proliferation after rapamycin application was estimated in a human SMC culture for time and dose dependent effects. RESULTS Rapamycin treatment resulted in a significant reduction of intima media ratio compared to vehicle treated animals after three weeks (0.65 +/- 0.1 vs. 1.2 +/- 0.2 intima-media-ratio, p < 0.05). 2D electrophoresis analysis proved increased ECM synthesis following angioplasty (i.e., lamin, vimentin) in vehicle treated animals. Local rapamycin administration resulted in profound reduction of ECM synthesis after vascular injury. In in-vitro experiments exposure of cultured human SMCs to rapamycin resulted in a significant and dose-dependent (1 nm-100 nm) reduction of human smooth muscle cell proliferation measured by cell counting. CONCLUSION These above mentioned results suggest that protein synthesis in addition to reduction of cellular proliferation plays an important role following vascular injury, since application of rapamycin resulted in the reduction of SMC proliferation and ECM-synthesis.
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MESH Headings
- Angioplasty, Balloon
- Animals
- Cell Division/drug effects
- Cell Movement/drug effects
- Cells, Cultured/drug effects
- Cells, Cultured/pathology
- Dose-Response Relationship, Drug
- Electrophoresis, Gel, Two-Dimensional
- Fibromuscular Dysplasia/pathology
- Humans
- Male
- Muscle Proteins/biosynthesis
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Rabbits
- Sirolimus/pharmacology
- Tunica Media/drug effects
- Tunica Media/pathology
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Affiliation(s)
- M Hilker
- Department of Thoracic and Cardiovascular Surgery, Johannes Gutenberg University, Mainz, Germany.
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41
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Schwertz H, Längin T, Platsch H, Richert J, Bomm S, Schmidt M, Hillen H, Blaschke G, Meyer J, Darius H, Buerke M. Two-dimensional analysis of myocardial protein expression following myocardial ischemia and reperfusion in rabbits. Proteomics 2002; 2:988-95. [PMID: 12203894 DOI: 10.1002/1615-9861(200208)2:8<988::aid-prot988>3.0.co;2-#] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Myocardial ischemia and reperfusion injury (MI/R) can be related to leukocyte activation with subsequent release of cytokines and oxygen derived free radicals. Activation of the complement system has been implicated in the pathogenesis of myocardial ischemia and reperfusion injury. Inflammatory injury will subsequently result in cellular activation and protein synthesis. In the present study we analyzed the myocardial protein expression and its pattern following myocardial ischemia and reperfusion, with and without complement inhibition with the synthetic serine protease inhibitor Futhan/nafamstat mesilate (FUT-175) known to inhibit classical and alternative complement pathway in a rabbit model of myocardial ischemia and reperfusion (60 min I+180 min R). FUT-175 significantly reduced myocardial necrosis, i.e. creatine kinase release which were analyzed for the three groups (p<0.05). Similarly, histological analysis demonstrated preservation of myocardial tissue injury and reduced leukocyte accumulation following FUT-175 treatment. Further, the myocardial protein expression was analyzed by two-dimensional gel electrophoresis following MI/R in the different groups. The protein patterns were evaluated by means of MELANIE III, a computer assisted gel analysis system. The biochemical identification of the proteins of interest was, achieved using nanohigh-performance liquid chromatography/electrospray ionization-tandem mass spectrometry. On average, 509 +/- 25 protein spots were found on the gels. A pattern of 480 spots with identical positions was found on every gel of five animals of each group. We analyzed ten spots which were significantly altered (i.e., in eight spots we observed decreased protein expression and in two spots we observed increased expression, vehicle vs. sham), by using mass spectrometry. Superoxide dismutase precursor and alphaB-crystallin were identified. We compared sham group vs. vehicle group and vehicle group vs. FUT-175 treated animals. Expression of the two identified proteins decreased by half the amount in the vehicle group when compared to sham treated animals. Treatment with FUT-175 preserved significantly superoxide dismutase precursor and alphaB-crystallin protein expression when compared to vehicle animals. The results present marked differences in myocardial protein expression after ischemia and reperfusion and following treatment with the complement inhibitor FUT-175. Our results illustrate the application of proteomics to discover possible new therapeutic targets or to detect unexpected effects of pharmacological inhibitors.
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Affiliation(s)
- Hansjörg Schwertz
- II Department of Medicine, Johannes Gutenberg University, Langenbeckstrasse 1, 55101 Mainz, Germany
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42
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Buerke M, Schwertz H, Seitz W, Meyer J, Darius H. Novel small molecule inhibitor of C1s exerts cardioprotective effects in ischemia-reperfusion injury in rabbits. J Immunol 2001; 167:5375-80. [PMID: 11673555 DOI: 10.4049/jimmunol.167.9.5375] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Myocardial ischemia-reperfusion injury can be related to complement activation with generation of chemotactic agents, adhesion molecule expression, release of cytokines and oxygen-derived free radicals, and subsequent neutrophil accumulation. In the present study the cardioprotective effects of a novel highly selective small molecule C1s inhibitor (C1s-INH-248, Knoll) were examined in a rabbit model of myocardial ischemia (I) and reperfusion (R; i.e., 60 min I + 180 min R). In in vitro tests (enzyme activity and SRBC lysis) C1s-INH-248 demonstrated profound inhibitory potency. In vivo C1s-INH-248 (1 mg/kg body weight) administered 5 min before reperfusion significantly attenuated myocardial injury (31.9 +/- 2.5 vs 8.9 +/- 1.6% necrosis/area at risk; p < 0.01). The cardioprotective effect was dose dependent. The reduction of myocardial injury was also observed as diminished plasma creatine kinase activity in C1s-INH-248-treated animals (70.7 +/- 6.8 vs 45.1 +/- 3.9 U/g protein after 3 h of reperfusion, p < 0.05). Further, cardiac myeloperoxidase activity (i.e., a marker of PMN accumulation) in the ischemic and necrotic area was significantly reduced following C1s-INH-248 treatment (1.31 +/- 0.23 vs 0.4 +/- 0.05 U/100 mg tissue in necrotic area, p < 0.01). Thus, blocking the classical complement pathway with a highly specific and potent synthetic inhibitor of the activated C1 complex appears to be an effective mean to preserve ischemic myocardium from injury following reperfusion.
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Affiliation(s)
- M Buerke
- Second Department of Medicine, Johannes Gutenberg University, Mainz, Germany.
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