1
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Yuan H, Liu Y, Zhang J, Dong JF, Zhao Z. Transcription factors in megakaryocytes and platelets. Front Immunol 2023; 14:1140501. [PMID: 36969155 PMCID: PMC10034027 DOI: 10.3389/fimmu.2023.1140501] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
Transcription factors bind promoter or regulatory sequences of a gene to regulate its rate of transcription. However, they are also detected in anucleated platelets. The transcription factors RUNX1, GATA1, STAT3, NFκB, and PPAR have been widely reported to play key roles in the pathophysiology of platelet hyper-reactivity, thrombosis, and atherosclerosis. These non-transcriptional activities are independent of gene transcription or protein synthesis but their underlying mechanisms of action remain poorly defined. Genetic and acquired defects in these transcription factors are associated with the production of platelet microvesicles that are known to initiate and propagate coagulation and to promote thrombosis. In this review, we summarize recent developments in the study of transcription factors in platelet generation, reactivity, and production of microvesicles, with a focus on non-transcriptional activities of selected transcription factors.
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Affiliation(s)
- Hengjie Yuan
- Tianjin Institute of Neurology, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- BloodWorks Research Institute, Seattle, WA, United States
| | - Yafan Liu
- Tianjin Institute of Neurology, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Jianning Zhang
- Tianjin Institute of Neurology, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Jing-fei Dong
- BloodWorks Research Institute, Seattle, WA, United States
- Division of Hematology, Department of Medicine, University of Washington, School of Medicine, Seattle, WA, United States
- *Correspondence: Zilong Zhao, ; Jing-fei Dong,
| | - Zilong Zhao
- Tianjin Institute of Neurology, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- BloodWorks Research Institute, Seattle, WA, United States
- *Correspondence: Zilong Zhao, ; Jing-fei Dong,
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Aqdas M, Sung MH. NF-κB dynamics in the language of immune cells. Trends Immunol 2023; 44:32-43. [PMID: 36473794 PMCID: PMC9811507 DOI: 10.1016/j.it.2022.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022]
Abstract
Biological discovery has been driven by advances in throughput and resolution of analysis technologies. They have also created an indelible bias for snapshot-based knowledge. Even though recent methods such as multi-omics single-cell assays have empowered immunological investigations, they still provide snapshots of cellular behaviors and thus, have inherent limitations in reconstructing unsynchronized dynamic events across individual cells. Here, we present a rationale for how NF-κB may convey specificity of contextual information through subtle quantitative features of its signaling dynamics. The next frontier of predictive understanding should involve functional characterization of NF-κB signaling dynamics and their immunological implications. This may help solve the apparent paradox that a ubiquitously activated transcription factor can shape accurate responses to different immune challenges.
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Affiliation(s)
- Mohammad Aqdas
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Myong-Hee Sung
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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3
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Tang BY, Ge J, Wu Y, Wen J, Tang XH. The Role of ADAM17 in Inflammation-Related Atherosclerosis. J Cardiovasc Transl Res 2022; 15:1283-1296. [PMID: 35648358 DOI: 10.1007/s12265-022-10275-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 05/06/2022] [Indexed: 10/18/2022]
Abstract
Atherosclerosis is a chronic inflammatory disease that poses a huge economic burden due to its extremely poor prognosis. Therefore, it is necessary to explore potential mechanisms to improve the prevention and treatment of atherosclerosis. A disintegrin and metalloprotease 17 (ADAM17) is a cell membrane-bound protein that performs a range of functions through membrane protein shedding and intracellular signaling. ADAM17-mediated inflammation has been identified to be an important contributor to atherosclerosis; however, the specific relationship between its multiple regulatory roles and the pathogenesis of atherosclerosis remains unclear. Here, we reviewed the activation, function, and regulation of ADAM17, described in detail the role of ADAM17-mediated inflammatory damage in atherosclerosis, and discussed several controversial points. We hope that these insights into ADAM17 biology will lead to rational management of atherosclerosis. ADAM17 promotes vascular inflammation in endothelial cells, smooth muscle cells, and macrophages, and regulates the occurrence and development of atherosclerosis.
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Affiliation(s)
- Bai-Yi Tang
- Department of Cardiology, Third Xiang-Ya Hospital, Central South University, 138 Tongzipo Road, Changsha, 410013, Hunan, China
| | - Jin Ge
- Department of Cardiology, Third Xiang-Ya Hospital, Central South University, 138 Tongzipo Road, Changsha, 410013, Hunan, China
| | - Yang Wu
- Department of Cardiology, Third Hospital of Changsha, 176 W. Laodong Road, Changsha, 410015, Hunan, China
| | - Juan Wen
- Department of Cardiology, Third Xiang-Ya Hospital, Central South University, 138 Tongzipo Road, Changsha, 410013, Hunan, China.
| | - Xiao-Hong Tang
- Department of Cardiology, Third Xiang-Ya Hospital, Central South University, 138 Tongzipo Road, Changsha, 410013, Hunan, China.
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4
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Sun Y, Liu R, Xia X, Xing L, Jiang J, Bian W, Zhang W, Wang C, Zhang C. Large-Scale Profiling on lncRNAs in Human Platelets: Correlation with Platelet Reactivity. Cells 2022; 11:cells11142256. [PMID: 35883699 PMCID: PMC9319970 DOI: 10.3390/cells11142256] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/12/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022] Open
Abstract
Recently, long noncoding RNAs (lncRNAs) have been key regulators for both mRNAs and proteins in nucleated cells. However, the expression profiles of lncRNAs in non-nucleated cells such as platelets are currently unclear. In this study, we determined the expression profiles of lncRNAs in human platelets. We found that 6109 lncRNAs were expressed in human platelets. Interestingly, 338 lncRNAs were differentially expressed in hyperreactive and hyporeactive platelets. Bioinformatics’ analysis revealed that these aberrantly expressed lncRNAs might be related to platelet activity and other platelet functions. To provide a proof of concept, we measured the expression levels of PARLncRNA-1, a down-regulated lncRNA of hyperreactive platelets, in platelets from 12 patients with acute myocardial infarction and their controls. We found that the lncRNA was also significantly down-regulated in platelets from patients, which was partially reversed by treatment with aspirin a known antiplatelet drug. LncRNAs may represent a novel class of modulators for platelet functions.
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Affiliation(s)
- Yeying Sun
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Rongrong Liu
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Xiangwen Xia
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Luchuan Xing
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Jing Jiang
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Weihua Bian
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
- Department of Biomedical Engineering, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Wendy Zhang
- Department of Biomedical Engineering, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Chunhua Wang
- US-China Institute for Translational Medicine, College of Pharmacy, Binzhou Medical University, Yantai 264000, China; (Y.S.); (R.L.); (X.X.); (L.X.); (J.J.); (W.B.); (C.W.)
| | - Chunxiang Zhang
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Key Laboratory of Medical Electrophysiology of Ministry of Education, Institute of Cardiovascular Research, Nucleic Acid Medicine of Luzhou Key Laboratory, Metabolic Vascular Disease Key Laboratory of Sichuan Province, Southwest Medical University, Luzhou 646000, China
- Correspondence: ; Tel.: +86-001-830-3162828
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Sun S, Han Y, Zhang C, Liu H, Wang B, Cao S, Yuan Q, Wei S, Chen Y. Adenosine Kinase Inhibition Prevents Severe Acute Pancreatitis via Suppressing Inflammation and Acinar Cell Necroptosis. Front Cell Dev Biol 2022; 10:827714. [PMID: 35281076 PMCID: PMC8904929 DOI: 10.3389/fcell.2022.827714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 02/07/2022] [Indexed: 12/14/2022] Open
Abstract
Background: Inflammatory disorder and acinar cell death contribute to the initiation and progression of severe acute pancreatitis (SAP). Adenosine kinase (ADK) has potential effects on both inflammation and cell death. However, the role of ADK in SAP remains to be explored. Methods: To establish an experimental SAP model, male C57BL/6 mice were intraperitoneally injected with cerulein (50 μg/kg, seven doses at hourly intervals) and LPS (10 mg/kg, at the last cerulein injection). For ADK inhibition, ABT702 (1.5 mg/kg) was intraperitoneally injected 1 h before cerulein treatment. The pancreas and serum were collected and analyzed to determine the severity of pancreatic injury and explore the potential pathophysiological mechanisms. Pancreatic acinar cells (AR42J) were used to explore the in vitro effects of ADK inhibition on cerulein–induced inflammation and necroptotic cell death. Results: ADK inhibition notably attenuated the severity of SAP, as indicated by the decreased serum amylase (7,416.76 ± 1,457.76 vs. 4,581.89 ± 1,175.04 U/L) and lipase (46.51 ± 11.50 vs. 32.94 ± 11.46 U/L) levels and fewer pancreatic histopathological alterations (histological scores: 6.433 ± 0.60 vs. 3.77 ± 0.70). MOMA-2 and CD11b staining confirmed that ADK inhibition prevented the infiltration of neutrophils and macrophages. The phosphorylation of nuclear factor-κB (NF-κB) was also reduced by ADK inhibition. ADK inhibition markedly limited the necrotic area of the pancreas and prevented the activation of the necroptotic signaling pathway. Endoplasmic reticulum (ER) stress was activated in the pancreas using the SAP model and cerulein–treated AR42J cells whereas ADK inhibition reversed the activation of ER stress both in vivo and in vitro. Moreover, the alleviating effects of ADK inhibition on ER stress, inflammation, and cell necroptosis were eliminated by the adenosine A2A receptor antagonist. Conclusion: ADK inhibition reduced inflammation and necroptotic acinar cell death in SAP via the adenosine A2A receptor/ER stress pathway, suggesting that ADK might be a potential therapeutic target for SAP.
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Affiliation(s)
- Shukun Sun
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Yu Han
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Chuanxin Zhang
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Han Liu
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Bailu Wang
- Clinical Trial Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Shengchuan Cao
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Qiuhuan Yuan
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
| | - Shujian Wei
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
- *Correspondence: Shujian Wei, ; Yuguo Chen,
| | - Yuguo Chen
- Department of Emergency and Chest Pain Center, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Shandong University, Jinan, China
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Chinese Ministry of Education, Qilu Hospital, Cheeloo College of Medicine, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Shandong University, Jinan, China
- *Correspondence: Shujian Wei, ; Yuguo Chen,
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El-Kadiry AEH, Merhi Y. The Role of the Proteasome in Platelet Function. Int J Mol Sci 2021; 22:3999. [PMID: 33924425 PMCID: PMC8069084 DOI: 10.3390/ijms22083999] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Platelets are megakaryocyte-derived acellular fragments prepped to maintain primary hemostasis and thrombosis by preserving vascular integrity. Although they lack nuclei, platelets harbor functional genomic mediators that bolster platelet activity in a signal-specific manner by performing limited de novo protein synthesis. Furthermore, despite their limited protein synthesis, platelets are equipped with multiple protein degradation mechanisms, such as the proteasome. In nucleated cells, the functions of the proteasome are well established and primarily include proteostasis among a myriad of other signaling processes. However, the role of proteasome-mediated protein degradation in platelets remains elusive. In this review article, we recapitulate the developing literature on the functions of the proteasome in platelets, discussing its emerging regulatory role in platelet viability and function and highlighting how its functional coupling with the transcription factor NF-κB constitutes a novel potential therapeutic target in atherothrombotic diseases.
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Affiliation(s)
- Abed El-Hakim El-Kadiry
- Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, Montreal, QC H1T 1C8, Canada;
- Biomedical Sciences Program, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Yahye Merhi
- Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, Montreal, QC H1T 1C8, Canada;
- Biomedical Sciences Program, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
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7
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Hsia CW, Wu MP, Shen MY, Hsia CH, Chung CL, Sheu JR. Regulation of Human Platelet Activation and Prevention of Arterial Thrombosis in Mice by Auraptene through Inhibition of NF-κB Pathway. Int J Mol Sci 2020; 21:ijms21134810. [PMID: 32646046 PMCID: PMC7370278 DOI: 10.3390/ijms21134810] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/21/2022] Open
Abstract
Platelets are major players in the occurrence of cardiovascular diseases. Auraptene is the most abundant coumarin derivative from plants, and it has been demonstrated to possess a potent capacity to inhibit platelet activation. Although platelets are anucleated cells, they also express the transcription factor, nuclear factor-κB (NF-κB), that may exert non-genomic functions in platelet activation. In the current study, we further investigated the inhibitory roles of auraptene in NF-κB-mediated signal events in platelets. MG-132 (an inhibitor of proteasome) and BAY11-7082 (an inhibitor of IκB kinase; IKK), obviously inhibited platelet aggregation; however, BAY11-7082 exhibited more potent activity than MG-132 in this reaction. The existence of NF-κB (p65) in platelets was observed by confocal microscopy, and auraptene attenuated NF-κB activation such as IκBα and p65 phosphorylation and reversed IκBα degradation in collagen-activated platelets. To investigate cellular signaling events between PLCγ2-PKC and NF-κB, we found that BAY11-7082 abolished PLCγ2-PKC activation; nevertheless, neither U73122 nor Ro31-8220 had effect on NF-κB activation. Furthermore, both auraptene and BAY11-7082 significantly diminished HO• formation in activated platelets. For in vivo study, auraptene prolonged the occlusion time of platelet plug in mice. In conclusion, we propose a novel inhibitory pathway of NF-κB-mediated PLCγ2-PKC activation by auraptene in human platelets, and further supported that auraptene possesses potent activity for thromboembolic diseases.
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Affiliation(s)
- Chih-Wei Hsia
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (C.-W.H.); (M.-P.W.); (C.-H.H.)
| | - Ming-Ping Wu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (C.-W.H.); (M.-P.W.); (C.-H.H.)
- Department of Obstetrics and Gynecology, Chi-Mei Medical Center, Tainan 710, Taiwan
| | - Ming-Yi Shen
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 404, Taiwan;
| | - Chih-Hsuan Hsia
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (C.-W.H.); (M.-P.W.); (C.-H.H.)
- Translational Medicine Center, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 111, Taiwan
| | - Chi-Li Chung
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (C.-W.H.); (M.-P.W.); (C.-H.H.)
- Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 110, Taiwan
- Correspondence: (C.-L.C.); (J.-R.S.); Tel.: +886-2-27372181 (C.-L.C.); Tel.: +886-2-27361661 (ext. 3199) (J.-R.S.)
| | - Joen-Rong Sheu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (C.-W.H.); (M.-P.W.); (C.-H.H.)
- Department of Pharmacology, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
- Correspondence: (C.-L.C.); (J.-R.S.); Tel.: +886-2-27372181 (C.-L.C.); Tel.: +886-2-27361661 (ext. 3199) (J.-R.S.)
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8
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Kojok K, Akoum SE, Mohsen M, Mourad W, Merhi Y. CD40L Priming of Platelets via NF-κB Activation is CD40- and TAK1-Dependent. J Am Heart Assoc 2019; 7:e03677. [PMID: 30571597 PMCID: PMC6405550 DOI: 10.1161/jaha.118.009636] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background CD40 ligand (CD40L) is a thromboinflammatory molecule that predicts cardiovascular events. CD40L is a strong activator of nuclear factor kappa B (NF‐κB) in platelets that primes and enhances platelet activation in response to thrombotic stimuli. In addition to its classical receptor CD40, CD40L binds αIIbβ3, α5β1, and αMβ2 in various cell types. However, the function of the different CD40L receptors on platelets remains unexplored. The present study aims to identify the receptors of CD40L, involved in platelet NF‐κB activation, their downstream signaling and their implication in platelet aggregation. Methods and Results We showed that platelets express CD40, αIIbβ3, and α5β1 and release CD40L in response to sCD40L stimulation. sCD40L alone dose‐dependently induced platelet NF‐κB activation; this effect was absent in CD40−/− mouse platelets and inhibited by the CD40 blockade, but was unaffected by the αIIbβ3 or α5β1 blockade in human platelets. sCD40L/CD40 axis activates transforming growth factor‐β‐activated kinase 1 upstream of NF‐κB. In functional studies, sCD40L alone did not affect platelet aggregation but potentiated the aggregation response in the presence of suboptimal doses of thrombin; this effect was abolished by CD40, transforming growth factor‐β‐activated kinase 1, and NF‐κB inhibitors. Conclusions CD40L primes platelets via signaling pathways involving CD40/transforming growth factor‐β‐activated kinase 1/NF‐κB, which predisposes platelets to enhanced activation and aggregation in response to thrombotic stimuli.
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Affiliation(s)
- Kevin Kojok
- 1 Laboratory of Thrombosis and Hemostasis Montreal Heart Institute, Research Centre Montreal QC Canada.,2 Faculty of Medicine Université de Montréal QC Canada
| | - Souhad El Akoum
- 1 Laboratory of Thrombosis and Hemostasis Montreal Heart Institute, Research Centre Montreal QC Canada.,2 Faculty of Medicine Université de Montréal QC Canada
| | - Mira Mohsen
- 1 Laboratory of Thrombosis and Hemostasis Montreal Heart Institute, Research Centre Montreal QC Canada.,2 Faculty of Medicine Université de Montréal QC Canada
| | - Walid Mourad
- 2 Faculty of Medicine Université de Montréal QC Canada.,3 Research Centre Centre Hospitalier de l'Université de Montréal QC Canada
| | - Yahye Merhi
- 1 Laboratory of Thrombosis and Hemostasis Montreal Heart Institute, Research Centre Montreal QC Canada.,2 Faculty of Medicine Université de Montréal QC Canada
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9
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Kojok K, El-Kadiry AEH, Merhi Y. Role of NF-κB in Platelet Function. Int J Mol Sci 2019; 20:E4185. [PMID: 31461836 PMCID: PMC6747346 DOI: 10.3390/ijms20174185] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/25/2019] [Accepted: 08/26/2019] [Indexed: 01/04/2023] Open
Abstract
Platelets are megakaryocyte-derived fragments lacking nuclei and prepped to maintain primary hemostasis by initiating blood clots on injured vascular endothelia. Pathologically, platelets undergo the same physiological processes of activation, secretion, and aggregation yet with such pronouncedness that they orchestrate and make headway the progression of atherothrombotic diseases not only through clot formation but also via forcing a pro-inflammatory state. Indeed, nuclear factor-κB (NF-κB) is largely implicated in atherosclerosis and its pathological complication in atherothrombotic diseases due to its transcriptional role in maintaining pro-survival and pro-inflammatory states in vascular and blood cells. On the other hand, we know little on the functions of platelet NF-κB, which seems to function in other non-genomic ways to modulate atherothrombosis. Therein, this review will resemble a rich portfolio for NF-κB in platelets, specifically showing its implications at the levels of platelet survival and function. We will also share the knowledge thus far on the effects of active ingredients on NF-κB in general, as an extrapolative method to highlight the potential therapeutic targeting of NF-κB in coronary diseases. Finally, we will unzip a new horizon on a possible extra-platelet role of platelet NF-κB, which will better expand our knowledge on the etiology and pathophysiology of atherothrombosis.
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Affiliation(s)
- Kevin Kojok
- The Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, 5000 Belanger Street, Montreal, H1T 1C8, QC, Canada
- Faculty of Medicine, Université de Montréal, Montreal, H3T 1J4, QC, Canada
| | - Abed El-Hakim El-Kadiry
- The Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, 5000 Belanger Street, Montreal, H1T 1C8, QC, Canada
- Faculty of Medicine, Université de Montréal, Montreal, H3T 1J4, QC, Canada
| | - Yahye Merhi
- The Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, 5000 Belanger Street, Montreal, H1T 1C8, QC, Canada.
- Faculty of Medicine, Université de Montréal, Montreal, H3T 1J4, QC, Canada.
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10
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Mussbacher M, Salzmann M, Brostjan C, Hoesel B, Schoergenhofer C, Datler H, Hohensinner P, Basílio J, Petzelbauer P, Assinger A, Schmid JA. Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis. Front Immunol 2019; 10:85. [PMID: 30778349 PMCID: PMC6369217 DOI: 10.3389/fimmu.2019.00085] [Citation(s) in RCA: 363] [Impact Index Per Article: 72.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 01/11/2019] [Indexed: 12/22/2022] Open
Abstract
The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.
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Affiliation(s)
- Marion Mussbacher
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Manuel Salzmann
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Christine Brostjan
- Department of Surgery, General Hospital, Medical University of Vienna, Vienna, Austria
| | - Bastian Hoesel
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | | | - Hannes Datler
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Philipp Hohensinner
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria
| | - José Basílio
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Peter Petzelbauer
- Skin and Endothelial Research Division, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Alice Assinger
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Johannes A Schmid
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
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11
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Karim ZA, Hensch NR, Qasim H, Alshbool FZ, Khasawneh FT. Role of IκB kinase β in regulating the remodeling of the CARMA1-Bcl10-MALT1 complex. Biochem Biophys Res Commun 2018; 500:268-274. [PMID: 29649481 DOI: 10.1016/j.bbrc.2018.04.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 04/09/2018] [Indexed: 01/26/2023]
Abstract
The current work investigates the notion that inducible clustering of signaling mediators of the IKK pathway is important for platelet activation. Thus, while the CARMA1, Bcl10, and MALT1 (CBM) complex is essential for triggering IKK/NF-κB activation upon platelet stimulation, the signals that elicit its formation and downstream effector activation remain elusive. We demonstrate herein that IKKβ is involved in membrane fusion, and serves as a critical protein kinase required for initial formation and the regulation of the CARMA1/MALT1/Bcl10/CBM complex in platelets. We also show that IKKβ regulates these processes via modulation of phosphorylation of Bcl10 and IKKγ polyubiquitination. Collectively, our data demonstrate that IKKβ regulates membrane fusion and the remodeling of the CBM complex formation.
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Affiliation(s)
- Zubair A Karim
- 1101 N. Campbell St, Pharmaceutical Sciences, School of Pharmacy, The University of Texas El Paso, El Paso, TX 79902, USA.
| | - Nicole R Hensch
- The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Hanan Qasim
- 1101 N. Campbell St, Pharmaceutical Sciences, School of Pharmacy, The University of Texas El Paso, El Paso, TX 79902, USA
| | - Fatima Z Alshbool
- 1101 N. Campbell St, Pharmaceutical Sciences, School of Pharmacy, The University of Texas El Paso, El Paso, TX 79902, USA
| | - Fadi T Khasawneh
- 1101 N. Campbell St, Pharmaceutical Sciences, School of Pharmacy, The University of Texas El Paso, El Paso, TX 79902, USA
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12
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Hirata S, Murata T, Suzuki D, Nakamura S, Jono‐Ohnishi R, Hirose H, Sawaguchi A, Nishimura S, Sugimoto N, Eto K. Selective Inhibition of ADAM17 Efficiently Mediates Glycoprotein Ibα Retention During Ex Vivo Generation of Human Induced Pluripotent Stem Cell-Derived Platelets. Stem Cells Transl Med 2016; 6:720-730. [PMID: 28297575 PMCID: PMC5442763 DOI: 10.5966/sctm.2016-0104] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 09/01/2016] [Indexed: 12/17/2022] Open
Abstract
Donor‐independent platelet concentrates for transfusion can be produced in vitro from induced pluripotent stem cells (iPSCs). However, culture at 37°C induces ectodomain shedding on platelets of glycoprotein Ibα (GPIbα), the von Willebrand factor receptor critical for adhesive function and platelet lifetime in vivo, through temperature‐dependent activation of a disintegrin and metalloproteinase 17 (ADAM17). The shedding can be suppressed by using inhibitors of panmetalloproteinases and possibly of the upstream regulator p38 mitogen‐activated protein kinase (p38 MAPK), but residues of these inhibitors in the final platelet products may be accompanied by harmful risks that prevent clinical application. Here, we optimized the culture conditions for generating human iPSC‐derived GPIbα+ platelets, focusing on culture temperature and additives, by comparing a new and safe selective ADAM17 inhibitor, KP‐457, with previous inhibitors. Because cultivation at 24°C (at which conventional platelet concentrates are stored) markedly diminished the yield of platelets with high expression of platelet receptors, 37°C was requisite for normal platelet production from iPSCs. KP‐457 blocked GPIbα shedding from iPSC platelets at a lower half‐maximal inhibitory concentration than panmetalloproteinase inhibitor GM‐6001, whereas p38 MAPK inhibitors did not. iPSC platelets generated in the presence of KP‐457 exhibited improved GPIbα‐dependent aggregation not inferior to human fresh platelets. A thrombus formation model using immunodeficient mice after platelet transfusion revealed that iPSC platelets generated with KP‐457 exerted better hemostatic function in vivo. Our findings suggest that KP‐457, unlike GM‐6001 or p38 MAPK inhibitors, effectively enhances the production of functional human iPSC‐derived platelets at 37°C, which is an important step toward their clinical application. Stem Cells Translational Medicine2017;6:720–730
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Affiliation(s)
- Shinji Hirata
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- Kaken Pharmaceutical Co., Ltd., Tokyo, Japan
| | | | - Daisuke Suzuki
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Sou Nakamura
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Ryoko Jono‐Ohnishi
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Hidenori Hirose
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- Kyoto Development Center, Megakaryon Co., Ltd., Kyoto, Japan
| | - Akira Sawaguchi
- Department of Anatomy, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Satoshi Nishimura
- Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Naoshi Sugimoto
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Koji Eto
- Department of Clinical Application, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- Department of Innovation Stem Cell Therapy, Chiba University Graduate School of Medicine, Chiba, Japan
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13
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Fuentes E, Rojas A, Palomo I. NF-κB signaling pathway as target for antiplatelet activity. Blood Rev 2016; 30:309-15. [PMID: 27075489 DOI: 10.1016/j.blre.2016.03.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 02/26/2016] [Accepted: 03/08/2016] [Indexed: 02/07/2023]
Abstract
In different nucleated cells, NF-κB has long been considered a prototypical proinflammatory signaling pathway with the expression of proinflammatory genes. Although platelets lack a nucleus, a number of functional transcription factors are involved in activated platelets, such as NF-κB. In platelet activation NF-κB regulation events include IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation. Multiple pathways contribute to platelet activation and NF-κB is a common pathway in this activation. Therefore, in platelet activation the modulation of NF-κB pathway could be a potential new target in the treatment of inflammation-related vascular disease therapy (antiplatelet and antithrombotic activities).
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Affiliation(s)
- Eduardo Fuentes
- Laboratory of Hematology and Immunology, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001, Talca, Chile.
| | - Armando Rojas
- Biomedical Research Laboratories, Medicine Faculty, Catholic University of Maule, Talca, Chile
| | - Iván Palomo
- Laboratory of Hematology and Immunology, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001, Talca, Chile.
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14
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Kuijpers MJ, Mattheij NJ, Cipolla L, van Geffen JP, Lawrence T, Donners MM, Boon L, Lievens D, Torti M, Noels H, Gerdes N, Cosemans JM, Lutgens E, Heemskerk JW. Platelet CD40L Modulates Thrombus Growth Via Phosphatidylinositol 3-Kinase β, and Not Via CD40 and IκB Kinase α. Arterioscler Thromb Vasc Biol 2015; 35:1374-81. [DOI: 10.1161/atvbaha.114.305127] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/15/2015] [Indexed: 12/17/2022]
Abstract
Objective—
To investigate the roles and signaling pathways of CD40L and CD40 in platelet–platelet interactions and thrombus formation under conditions relevant for atherothrombosis.
Approach and Results—
Platelets from mice prone to atherosclerosis lacking CD40L (
Cd40lg
−/−
Apoe
−/−
) showed diminished α
IIb
β
3
activation and α-granule secretion in response to glycoprotein VI stimulation, whereas these responses of CD40-deficient platelets (
Cd40
−/−
Apoe
−/−
) were not decreased. Using blood from
Cd40lg
−/−
Apoe
−/−
and
Cd40
−/−
Apoe
−/−
mice, the glycoprotein VI-dependent formation of dense thrombi was impaired on atherosclerotic plaque material or on collagen, in comparison with
Apoe
−/−
blood. In all genotypes, addition of CD40L to the blood enhanced the growth of dense thrombi on plaques and collagen. Similarly, CD40L enhanced glycoprotein VI–induced platelet aggregation, even with platelets deficient in CD40. This potentiation was antagonized in
Pik3cb
R/R
platelets or by inhibiting phosphatidylinositol 3-kinase β (PI3Kβ). Addition of CD40L also enhanced collagen-induced Akt phosphorylation, which was again antagonized by absence or inhibition of PI3Kβ. Finally, platelets from
Chuk1
A/A
Apoe
−/−
mice deficient in IκB kinase α (IKKα), implicated in CD40 signaling to nuclear factor (NF) κB, showed unchanged responses to CD40L in aggregation or thrombus formation.
Conclusions—
Under atherogenic conditions, CD40L enhances collagen-induced platelet–platelet interactions by supporting integrin α
IIb
β
3
activation, secretion and thrombus growth via PI3Kβ, but not via CD40 and IKKα/NFκB. This role of CD40L exceeds the no more than modest role of CD40 in thrombus formation.
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Affiliation(s)
- Marijke J.E. Kuijpers
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Nadine J.A. Mattheij
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Lina Cipolla
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Johanna P. van Geffen
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Toby Lawrence
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Marjo M.P.C. Donners
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Louis Boon
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Dirk Lievens
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Mauro Torti
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Heidi Noels
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Norbert Gerdes
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Judith M.E.M. Cosemans
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Esther Lutgens
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
| | - Johan W.M. Heemskerk
- From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d’Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians
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15
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Karim ZA, Vemana HP, Khasawneh FT. MALT1-ubiquitination triggers non-genomic NF-κB/IKK signaling upon platelet activation. PLoS One 2015; 10:e0119363. [PMID: 25748427 PMCID: PMC4352082 DOI: 10.1371/journal.pone.0119363] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/13/2015] [Indexed: 11/19/2022] Open
Abstract
We have recently shown that IKK complex plays an important non-genomic role in platelet function, i.e., regulates SNARE machinery-dependent membrane fusion. In this connection, it is well known that MALT1, whose activity is modulated by proteasome, plays an important role in the regulation of IKK complex. Therefore, the present studies investigated the mechanism by which IKK signaling is regulated in the context of the platelet proteasome. It was found that platelets express a functional proteasome, and form CARMA/MALT1/Bcl10 (CBM) complex when activated. Using a pharmacological inhibitor, the proteasome was found to regulate platelet function (aggregation, integrin activation, secretion, phosphatidylserine exposure and changes in intracellular calcium). It was also found to regulate thrombogenesis and physiologic hemostasis. We also observed, upon platelet activation, that MALT1 is ubiquitinated, and this coincides with the activation of the IKK/NF-κB-signaling pathway. Finally, we observed that the proteasome inhibitor blocks CBM complex formation and the interaction of IKKγ and MALT1; abrogates SNARE formation, and the association of MALT1 with TAK1 and TAB2, which are upstream of the CBM complex. Thus, our data demonstrate that MALT1 ubiquitination is critical for the engagement of CBM and IKK complexes, thereby directing platelet signals to the NF-κB pathway.
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Affiliation(s)
- Zubair A. Karim
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, 91766, United States of America
- * E-mail:
| | - Hari Priya Vemana
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, 91766, United States of America
| | - Fadi T. Khasawneh
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, 91766, United States of America
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16
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Cellular fibronectin containing extra domain A promotes arterial thrombosis in mice through platelet Toll-like receptor 4. Blood 2015; 125:3164-72. [PMID: 25700433 DOI: 10.1182/blood-2014-10-608653] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/11/2015] [Indexed: 12/19/2022] Open
Abstract
Cellular fibronectin containing extra domain A (Fn-EDA+), which is produced in response to tissue injury in several disease states, has prothrombotic activity and is known to interact with Toll-like-receptor 4 (TLR4). The underlying mechanism and cell types involved in mediating the prothrombotic effect of Fn-EDA+ still remain unknown. Using intravital microscopy, we evaluated susceptibility to carotid artery thrombosis after FeCl3-induced injury in mice expressing Fn lacking EDA (Fn-EDA(-/-) mice) or Fn containing EDA (Fn-EDA(+/+) mice). Fn-EDA(-/-) mice exhibited prolonged times to first thrombus formation and complete occlusion and a significant decrease in the rate of thrombus growth (P < .05 vs Fn-EDA(+/+) mice). Genetic deletion of TLR4 reversed the accelerated thrombosis in Fn-EDA(+/+) mice (P < .05) but had no effect in Fn-EDA(-/-) mice. Bone marrow transplantation experiments revealed that TLR4 expressed on hematopoietic cells contributes to accelerated thrombosis in Fn-EDA(+/+) mice. In vitro studies showed that cellular Fn-EDA+ interacts with platelet TLR4 and promotes agonist-induced platelet aggregation. Finally, Fn-EDA(+/+) mice specifically lacking platelet TLR4 exhibited prolonged times to first thrombus formation and complete occlusion (P < .05 vs Fn-EDA(+/+) mice containing platelet TLR4). We conclude that platelet TLR4 contributes to the prothrombotic effect of cellular Fn-EDA+, suggesting another link between thrombosis and innate immunity.
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Lannan KL, Sahler J, Kim N, Spinelli SL, Maggirwar SB, Garraud O, Cognasse F, Blumberg N, Phipps RP. Breaking the mold: transcription factors in the anucleate platelet and platelet-derived microparticles. Front Immunol 2015; 6:48. [PMID: 25762994 PMCID: PMC4327621 DOI: 10.3389/fimmu.2015.00048] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/26/2015] [Indexed: 01/15/2023] Open
Abstract
Platelets are small anucleate blood cells derived from megakaryocytes. In addition to their pivotal roles in hemostasis, platelets are the smallest, yet most abundant, immune cells and regulate inflammation, immunity, and disease progression. Although platelets lack DNA, and thus no functional transcriptional activities, they are nonetheless rich sources of RNAs, possess an intact spliceosome, and are thus capable of synthesizing proteins. Previously, it was thought that platelet RNAs and translational machinery were remnants from the megakaryocyte. We now know that the initial description of platelets as "cellular fragments" is an antiquated notion, as mounting evidence suggests otherwise. Therefore, it is reasonable to hypothesize that platelet transcription factors are not vestigial remnants from megakaryocytes, but have important, if only partly understood functions. Proteins play multiple cellular roles to minimize energy expenditure for maximum cellular function; thus, the same can be expected for transcription factors. In fact, numerous transcription factors have non-genomic roles, both in platelets and in nucleated cells. Our lab and others have discovered the presence and non-genomic roles of transcription factors in platelets, such as the nuclear factor kappa β (NFκB) family of proteins and peroxisome proliferator-activated receptor gamma (PPARγ). In addition to numerous roles in regulating platelet activation, functional transcription factors can be transferred to vascular and immune cells through platelet microparticles. This method of transcellular delivery of key immune molecules may be a vital mechanism by which platelet transcription factors regulate inflammation and immunity. At the very least, platelets are an ideal model cell to dissect out the non-genomic roles of transcription factors in nucleated cells. There is abundant evidence to suggest that transcription factors in platelets play key roles in regulating inflammatory and hemostatic functions.
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Affiliation(s)
- Katie L Lannan
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Julie Sahler
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA ; Department of Biological and Environmental Engineering, Cornell University , Ithaca, NY , USA
| | - Nina Kim
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Sherry L Spinelli
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Sanjay B Maggirwar
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Olivier Garraud
- Faculté de Médecine, Université de Lyon , Saint-Etienne , France
| | - Fabrice Cognasse
- Faculté de Médecine, Université de Lyon , Saint-Etienne , France ; Etablissement Français du Sang Auvergne-Loire , Saint-Etienne , France
| | - Neil Blumberg
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Richard P Phipps
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA ; Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA ; Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
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Affiliation(s)
- Mirta Schattner
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine-CONICET, National Academy of Medicine, Buenos Aires, Argentina
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Rivadeneyra L, Carestia A, Etulain J, Pozner RG, Fondevila C, Negrotto S, Schattner M. Regulation of platelet responses triggered by Toll-like receptor 2 and 4 ligands is another non-genomic role of nuclear factor-kappaB. Thromb Res 2013; 133:235-43. [PMID: 24331207 DOI: 10.1016/j.thromres.2013.11.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/06/2013] [Accepted: 11/26/2013] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Platelets express Toll-like receptors (TLRs) that recognise molecular components of pathogens and, in nucleated cells, elicit immune responses through nuclear factor-kappaB (NF-κB) activation. We have shown that NF-κB mediates platelet activation in response to classical agonists, suggesting that this transcription factor exerts non-genomic functions in platelets. The aim of this study was to determine whether NF-κB activation is a downstream signal involved in TLR2 and 4-mediated platelet responses. MATERIAL AND METHODS Aggregation and ATP release were measured with a Lumi-aggregometer. Fibrinogen binding, P-selectin and CD40 ligand (CD40L) levels and platelet-neutrophil aggregates were measured by cytometry. I kappa B alpha (IκBα) degradation and p65 phosphorylation were determined by Western blot and von Willebrand factor (vWF) by ELISA. RESULTS Platelet stimulation with Pam3CSK4 or LPS resulted in IκBα degradation and p65 phosphorylation. These responses were suppressed by TLR2 and 4 blocking and synergised by thrombin. Aggregation, fibrinogen binding and ATP and vWF release were triggered by Pam3CSK4. LPS did not induce platelet responses per se, except for vWF release, but it did potentiate thrombin-induced aggregation, fibrinogen binding and ATP secretion. Pam3CSK4, but not LPS, induced P-selectin and CD40L expression and mixed aggregate formation. All of these responses, except for CD40L expression, were inhibited in platelets treated with the NF-κB inhibitors BAY 11-7082 or Ro 106-9920. CONCLUSION TLR2 and 4 agonists trigger platelet activation responses through NF-κB. These data show another non-genomic function of NF-κB in platelets and highlight this molecule as a potential target to prevent platelet activation in inflammatory or infectious diseases.
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Affiliation(s)
- Leonardo Rivadeneyra
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina
| | - Agostina Carestia
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina
| | - Julia Etulain
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina
| | - Roberto G Pozner
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina
| | - Carlos Fondevila
- Service of Hematology, Bazterrica Clinic, Buenos Aires, Argentina
| | - Soledad Negrotto
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina
| | - Mirta Schattner
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine (CONICET), National Academy of Medicine, Buenos Aires, Argentina.
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Kruss S, Erpenbeck L, Amschler K, Mundinger TA, Boehm H, Helms HJ, Friede T, Andrews RK, Schön MP, Spatz JP. Adhesion maturation of neutrophils on nanoscopically presented platelet glycoprotein Ibα. ACS NANO 2013; 7:9984-96. [PMID: 24093566 PMCID: PMC4122703 DOI: 10.1021/nn403923h] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Neutrophilic granulocytes play a fundamental role in cardiovascular disease. They interact with platelet aggregates via the integrin Mac-1 and the platelet receptor glycoprotein Ibα (GPIbα). In vivo, GPIbα presentation is highly variable under different physiological and pathophysiological conditions. Here, we quantitatively determined the conditions for neutrophil adhesion in a biomimetic in vitro system, which allowed precise adjustment of the spacings between human GPIbα presented on the nanoscale from 60 to 200 nm. Unlike most conventional nanopatterning approaches, this method provided control over the local receptor density (spacing) rather than just the global receptor density. Under physiological flow conditions, neutrophils required a minimum spacing of GPIbα molecules to successfully adhere. In contrast, under low-flow conditions, neutrophils adhered on all tested spacings with subtle but nonlinear differences in cell response, including spreading area, spreading kinetics, adhesion maturation, and mobility. Surprisingly, Mac-1-dependent neutrophil adhesion was very robust to GPIbα density variations up to 1 order of magnitude. This complex response map indicates that neutrophil adhesion under flow and adhesion maturation are differentially regulated by GPIbα density. Our study reveals how Mac-1/GPIbα interactions govern cell adhesion and how neutrophils process the number of available surface receptors on the nanoscale. In the future, such in vitro studies can be useful to determine optimum therapeutic ranges for targeting this interaction.
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Affiliation(s)
- Sebastian Kruss
- Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, and Institute of Physical Chemistry, Heidelberg University, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Luise Erpenbeck
- Department of Dermatology, Venereology and Allergology, University Medical Center Göttingen, 40 Robert-Koch-Straße, Göttingen 37075, Germany
| | - Katharina Amschler
- Department of Dermatology, Venereology and Allergology, University Medical Center Göttingen, 40 Robert-Koch-Straße, Göttingen 37075, Germany
| | - Tabea A. Mundinger
- Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, and Institute of Physical Chemistry, Heidelberg University, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Heike Boehm
- Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, and Institute of Physical Chemistry, Heidelberg University, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Hans-Joachim Helms
- Department of Medical Statistics, University Medical Center Göttingen, 32 Humboldtallee, Göttingen 37073, Germany
| | - Tim Friede
- Department of Medical Statistics, University Medical Center Göttingen, 32 Humboldtallee, Göttingen 37073, Germany
| | - Robert K. Andrews
- Australian Center for Blood Diseases, Monash University, 89 Commercial Road, Melbourne 3004, Australia
| | - Michael P. Schön
- Department of Dermatology, Venereology and Allergology, University Medical Center Göttingen, 40 Robert-Koch-Straße, Göttingen 37075, Germany
- Address correspondence to ,
| | - Joachim P. Spatz
- Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, and Institute of Physical Chemistry, Heidelberg University, Heisenbergstraße 3, Stuttgart 70569, Germany
- Address correspondence to ,
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Abstract
Platelet secretion plays a key role in thrombosis, thus the platelet secretory machinery offers a unique target to modulate hemostasis. We report the regulation of platelet secretion via phosphorylation of SNAP-23 at Ser95. Phosphorylation of this t-soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) occurs upon activation of known elements of the platelet signaling cascades (ie, phospholipase C, [Ca(2+)]i, protein kinase C) and requires IκB kinase (IKK)-β. Other elements of the nuclear factor κB/IκB cascade (ie, IKK-α,-β,-γ/NEMO and CARMA/MALT1/Bcl10 complex) are present in anucleate platelets and IκB is phosphorylated upon activation, suggesting that this pathway is active in platelets and implying a nongenomic role for IKK. Inhibition of IKK-β, either pharmacologically (with BMS-345541, BAY11-7082, or TPCA-1) or by genetic manipulation (platelet factor 4 Cre:IKK-β(flox/flox)), blocked SNAP-23 phosphorylation, platelet secretion, and SNARE complex formation; but, had no effect on platelet morphology or other metrics of platelet activation. Consistently, SNAP-23 phosphorylation enhanced membrane fusion of SNARE-containing proteoliposomes. In vivo studies with IKK inhibitors or platelet-specific IKK-β knockout mice showed that blocking IKK-β activity significantly prolonged tail bleeding times, suggesting that currently available IKK inhibitors may affect hemostasis.
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