1
|
Antao NV, Sall J, Petzold C, Ekiert DC, Bhabha G, Liang FX. Sample preparation and data collection for serial block face scanning electron microscopy of mammalian cell monolayers. PLoS One 2024; 19:e0301284. [PMID: 39121154 PMCID: PMC11315281 DOI: 10.1371/journal.pone.0301284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 02/26/2024] [Indexed: 08/11/2024] Open
Abstract
Volume electron microscopy encompasses a set of electron microscopy techniques that can be used to examine the ultrastructure of biological tissues and cells in three dimensions. Two block face techniques, focused ion beam scanning electron microscopy (FIB-SEM) and serial block face scanning electron microscopy (SBF-SEM) have often been used to study biological tissue samples. More recently, these techniques have been adapted to in vitro tissue culture samples. Here we describe step-by-step protocols for two sample embedding methods for in vitro tissue culture cells intended to be studied using SBF-SEM. The first focuses on cell pellet embedding and the second on en face embedding. En face embedding can be combined with light microscopy, and this CLEM workflow can be used to identify specific biological events by light microscopy, which can then be imaged using SBF-SEM. We systematically outline the steps necessary to fix, stain, embed and image adherent tissue culture cell monolayers by SBF-SEM. In addition to sample preparation, we discuss optimization of parameters for data collection. We highlight the challenges and key steps of sample preparation, and the consideration of imaging variables.
Collapse
Affiliation(s)
- Noelle V. Antao
- Department of Cell Biology, New York University School of Medicine, New York, NY, United States of America
| | - Joseph Sall
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, United States of America
| | - Christopher Petzold
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, United States of America
| | - Damian C. Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY, United States of America
- Department of Microbiology, New York University School of Medicine, New York, NY, United States of America
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY, United States of America
| | - Feng-Xia Liang
- Department of Cell Biology, New York University School of Medicine, New York, NY, United States of America
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, United States of America
| |
Collapse
|
2
|
Scalise A, Aggarwal A, Sangwan N, Hamer A, Guntupalli S, Park HE, Aleman JO, Cameron SJ. A Divergent Platelet Transcriptome in Patients with Lipedema and Lymphedema. Genes (Basel) 2024; 15:737. [PMID: 38927673 PMCID: PMC11202821 DOI: 10.3390/genes15060737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
Lipedema and lymphedema are physically similar yet distinct diseases that are commonly misdiagnosed. We previously reported that lipedema and lymphedema are associated with increased risk for venous thromboembolism (VTE). The underlying etiology of the prothrombotic profile observed in lipedema and lymphedema is unclear, but may be related to alterations in platelets. Our objective was to analyze the platelet transcriptome to identify biological pathways that may provide insight into platelet activation and thrombosis. The platelet transcriptome was evaluated in patients with lymphedema and lipedema, then compared to control subjects with obesity. Patients with lipedema were found to have a divergent transcriptome from patients with lymphedema. The platelet transcriptome and impacted biological pathways in lipedema were surprisingly similar to weight-matched comparators, yet different when compared to overweight individuals with a lower body mass index (BMI). Differences in the platelet transcriptome for patients with lipedema and lymphedema were found in biological pathways required for protein synthesis and degradation, as well as metabolism. Key differences in the platelet transcriptome for patients with lipedema compared to BMI-matched subjects involved metabolism and glycosaminoglycan processing. These inherent differences in the platelet transcriptome warrant further investigation, and may contribute to the increased risk of thrombosis in patients with lipedema and lymphedema.
Collapse
Affiliation(s)
- Alliefair Scalise
- Heart Vascular and Thoracic Institute, Department of Cardiovascular Medicine, Section of Vascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Anu Aggarwal
- Lerner Research Institute, Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Naseer Sangwan
- Lerner Research Institute, Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Annelise Hamer
- Heart Vascular and Thoracic Institute, Department of Cardiovascular Medicine, Section of Vascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Suman Guntupalli
- Lerner Research Institute, Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Huijun Edelyn Park
- Lerner Research Institute, Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Jose O. Aleman
- Holman Division of Endocrinology, New York University, New York, NY 10012, USA;
| | - Scott J. Cameron
- Heart Vascular and Thoracic Institute, Department of Cardiovascular Medicine, Section of Vascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Lerner Research Institute, Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
- Department of Hematology, Taussig Cancer Center, Cleveland, OH 44195, USA
| |
Collapse
|
3
|
Manole CG, Soare C, Ceafalan LC, Voiculescu VM. Platelet-Rich Plasma in Dermatology: New Insights on the Cellular Mechanism of Skin Repair and Regeneration. Life (Basel) 2023; 14:40. [PMID: 38255655 PMCID: PMC10817627 DOI: 10.3390/life14010040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/30/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024] Open
Abstract
The skin's recognised functions may undergo physiological alterations due to ageing, manifesting as varying degrees of facial wrinkles, diminished tautness, density, and volume. Additionally, these functions can be disrupted (patho)physiologically through various physical and chemical injuries, including surgical trauma, accidents, or chronic conditions like ulcers associated with diabetes mellitus, venous insufficiency, or obesity. Advancements in therapeutic interventions that boost the skin's innate regenerative abilities could significantly enhance patient care protocols. The application of Platelet-Rich Plasma (PRP) is widely recognized for its aesthetic and functional benefits to the skin. Yet, the endorsement of PRP's advantages often borders on the dogmatic, with its efficacy commonly ascribed solely to the activation of fibroblasts by the factors contained within platelet granules. PRP therapy is a cornerstone of regenerative medicine which involves the autologous delivery of conditioned plasma enriched by platelets. This is achieved by centrifugation, removing erythrocytes while retaining platelets and their granules. Despite its widespread use, the precise sequences of cellular activation, the specific cellular players, and the molecular machinery that drive PRP-facilitated healing are still enigmatic. There is still a paucity of definitive and robust studies elucidating these mechanisms. In recent years, telocytes (TCs)-a unique dermal cell population-have shown promising potential for tissue regeneration in various organs, including the dermis. TCs' participation in neo-angiogenesis, akin to that attributed to PRP, and their role in tissue remodelling and repair processes within the interstitia of several organs (including the dermis), offer intriguing insights. Their potential to contribute to, or possibly orchestrate, the skin regeneration process following PRP treatment has elicited considerable interest. Therefore, pursuing a comprehensive understanding of the cellular and molecular mechanisms at work, particularly those involving TCs, their temporal involvement in structural recovery following injury, and the interconnected biological events in skin wound healing and regeneration represents a compelling field of study.
Collapse
Affiliation(s)
- Catalin G. Manole
- Department of Cellular and Molecular Biology and Histology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Ultrastructural Pathology Laboratory, “Victor Babeș” National Institute of Pathology, 050096 Bucharest, Romania
| | - Cristina Soare
- Department of Oncological Dermatology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Laura Cristina Ceafalan
- Department of Cellular and Molecular Biology and Histology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Cell Biology, Neurosciences and Experimental Myology Laboratory, “Victor Babeș” National Institute of Pathology, 050096 Bucharest, Romania
| | - Vlad M. Voiculescu
- Department of Oncological Dermatology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| |
Collapse
|
4
|
Fang L, Yu S, Tian X, Fu W, Su L, Chen Z, Yan C, He J, Hong J, Lian W, Liu G, Zhang Y, Zhou J, Hu L. Severe fever with thrombocytopenia syndrome virus replicates in platelets and enhances platelet activation. J Thromb Haemost 2023; 21:1336-1351. [PMID: 36792011 DOI: 10.1016/j.jtha.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/15/2023]
Abstract
BACKGROUND Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) infection causes an emerging hemorrhagic fever in East Asia with a high mortality rate. Thrombocytopenia is a consistent feature of SFTS illness, but the mechanism remains elusive. OBJECTIVES We aimed to better understand the role of platelets in the pathophysiology of SFTSV infection, including the development of thrombocytopenia. METHODS Using platelets from healthy volunteers and patients with SFTS, we evaluated the functional changes in platelets against SFTSV infection. We investigated the direct effect of glycoprotein VI on platelet-SFTSV interaction by quantitative real-time PCR, molecular docking, surface plasmon resonance spectrometry, flow cytometry, western blot, and platelet functional studies in vitro. Interactions of SFTSV and platelet-SFTSV complexes with macrophages were also determined by scanning electron microscope, quantitative real-time PCR, and flow cytometry. RESULTS This study is the first to demonstrate that platelets are capable of harboring and producing SFTSV particles. Structural and functional studies found that SFTSVs bind platelet glycoprotein VI to potentiate platelet activation, including platelet aggregation, adenosine triphosphate release, spreading, clot retraction, coagulation, phosphatidylserine exposure, thrombus formation, and adherence. In vitro mechanistic studies highlighted that the interaction of platelets with human THP-1 cells promoted SFTSV clearance and suppressed cytokine production in macrophages. However, unwanted SFTSV replication in macrophages reciprocally aggravated SFTSV persistence in the circulation, which may contribute to thrombocytopenia and other complications during SFTSV infection. CONCLUSION These findings together highlighted the pathophysiological role of platelets in initial intrinsic defense against SFTSV infections, as well as intertwined processes with host immunity, which can also lead to thrombocytopenia and poor prognosis.
Collapse
Affiliation(s)
- Lei Fang
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Zhejiang Provincial Centers for Disease Control and Prevention, Hangzhou, China; Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Sicong Yu
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiaoxu Tian
- Department of Cardiology, Cardiovascular Center, Henan Key Laboratory of Hereditary, Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Wanrong Fu
- Department of Cardiology, Cardiovascular Center, Henan Key Laboratory of Hereditary, Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Lingxuan Su
- Zhejiang Provincial Centers for Disease Control and Prevention, Hangzhou, China
| | - Zhi Chen
- National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Hangzhou, China
| | - Chunlan Yan
- Department of Biophysics, College of Medicine, Zhejiang University, Hangzhou, China
| | - Ji He
- Blood Center of Zhejiang Province, Hangzhou, China
| | - Jin Hong
- Department of Cardiology, Cardiovascular Center, Henan Key Laboratory of Hereditary, Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Wenwen Lian
- National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Hangzhou, China
| | - Gangqiong Liu
- Department of Cardiology, Cardiovascular Center, Henan Key Laboratory of Hereditary, Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yanjun Zhang
- Zhejiang Provincial Centers for Disease Control and Prevention, Hangzhou, China.
| | - Jiancang Zhou
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China.
| | - Liang Hu
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Department of Cardiology, Cardiovascular Center, Henan Key Laboratory of Hereditary, Cardiovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China; Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| |
Collapse
|
5
|
Jahanbani F, Maynard RD, Sing JC, Jahanbani S, Perrino JJ, Spacek DV, Davis RW, Snyder MP. Phenotypic characteristics of peripheral immune cells of Myalgic encephalomyelitis/chronic fatigue syndrome via transmission electron microscopy: A pilot study. PLoS One 2022; 17:e0272703. [PMID: 35943990 PMCID: PMC9362953 DOI: 10.1371/journal.pone.0272703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 07/25/2022] [Indexed: 01/06/2023] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex chronic multi-systemic disease characterized by extreme fatigue that is not improved by rest, and worsens after exertion, whether physical or mental. Previous studies have shown ME/CFS-associated alterations in the immune system and mitochondria. We used transmission electron microscopy (TEM) to investigate the morphology and ultrastructure of unstimulated and stimulated ME/CFS immune cells and their intracellular organelles, including mitochondria. PBMCs from four participants were studied: a pair of identical twins discordant for moderate ME/CFS, as well as two age- and gender- matched unrelated subjects-one with an extremely severe form of ME/CFS and the other healthy. TEM analysis of CD3/CD28-stimulated T cells suggested a significant increase in the levels of apoptotic and necrotic cell death in T cells from ME/CFS patients (over 2-fold). Stimulated Tcells of ME/CFS patients also had higher numbers of swollen mitochondria. We also found a large increase in intracellular giant lipid droplet-like organelles in the stimulated PBMCs from the extremely severe ME/CFS patient potentially indicative of a lipid storage disorder. Lastly, we observed a slight increase in platelet aggregation in stimulated cells, suggestive of a possible role of platelet activity in ME/CFS pathophysiology and disease severity. These results indicate extensive morphological alterations in the cellular and mitochondrial phenotypes of ME/CFS patients' immune cells and suggest new insights into ME/CFS biology.
Collapse
Affiliation(s)
- Fereshteh Jahanbani
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Rajan D. Maynard
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Justin Cyril Sing
- Department of Molecular Genetics, Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Shaghayegh Jahanbani
- Division of Immunology and Rheumatology, Stanford University School of Medicine, and VA Palo Alto Health Care System, Palo Alto, California, United States of America
| | - John J. Perrino
- Stanford Cell Sciences Imaging Facility (CSIF), Stanford University School of Medicine Stanford, Stanford, California, United States of America
| | - Damek V. Spacek
- Karius Incorporated, Redwood City, California, United States of America
| | - Ronald W. Davis
- ME/CFS Collaborative Research Center at Stanford, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California, United States of America
| | - Michael P. Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| |
Collapse
|
6
|
Veuthey L, Aliotta A, Bertaggia Calderara D, Pereira Portela C, Alberio L. Mechanisms Underlying Dichotomous Procoagulant COAT Platelet Generation-A Conceptual Review Summarizing Current Knowledge. Int J Mol Sci 2022; 23:2536. [PMID: 35269679 PMCID: PMC8910683 DOI: 10.3390/ijms23052536] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/19/2022] [Accepted: 02/21/2022] [Indexed: 12/23/2022] Open
Abstract
Procoagulant platelets are a subtype of activated platelets that sustains thrombin generation in order to consolidate the clot and stop bleeding. This aspect of platelet activation is gaining more and more recognition and interest. In fact, next to aggregating platelets, procoagulant platelets are key regulators of thrombus formation. Imbalance of both subpopulations can lead to undesired thrombotic or bleeding events. COAT platelets derive from a common pro-aggregatory phenotype in cells capable of accumulating enough cytosolic calcium to trigger specific pathways that mediate the loss of their aggregating properties and the development of new adhesive and procoagulant characteristics. Complex cascades of signaling events are involved and this may explain why an inter-individual variability exists in procoagulant potential. Nowadays, we know the key agonists and mediators underlying the generation of a procoagulant platelet response. However, we still lack insight into the actual mechanisms controlling this dichotomous pattern (i.e., procoagulant versus aggregating phenotype). In this review, we describe the phenotypic characteristics of procoagulant COAT platelets, we detail the current knowledge on the mechanisms of the procoagulant response, and discuss possible drivers of this dichotomous diversification, in particular addressing the impact of the platelet environment during in vivo thrombus formation.
Collapse
Affiliation(s)
| | | | | | | | - Lorenzo Alberio
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (L.V.); (A.A.); (D.B.C.); (C.P.P.)
| |
Collapse
|
7
|
Bura A, Jurak Begonja A. Imaging of Intracellular and Plasma Membrane Pools of PI(4,5)P 2 and PI4P in Human Platelets. Life (Basel) 2021; 11:1331. [PMID: 34947862 PMCID: PMC8705196 DOI: 10.3390/life11121331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/23/2021] [Accepted: 11/28/2021] [Indexed: 12/25/2022] Open
Abstract
Phosphoinositides (PIs) are phosphorylated membrane lipids that have a plethora of roles in the cell, including vesicle trafficking, signaling, and actin reorganization. The most abundant PIs in the cell are phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] and phosphatidylinositol-4-monophosphate (PI4P). The localization and roles of both PI(4,5)P2 and PI4P are well established, is the broadly accepted methodological approach for their immunocytochemical visualization in different cell compartments in several cell lines. However, not much is known about these PIs in platelets (PLTs), the smallest blood cells that detect vessel wall injury, activate, and stop the bleeding. Therefore, we sought to investigate the localization of PI(4,5)P2 and PI4P in resting and activated PLTs by antibody staining. Here, we show that the intracellular pools of PI(4,5)P2 and PI4P can be detected by the established staining protocol, and these pools can be modulated by inhibitors of OCRL phosphatase and PI4KIIIα kinase. However, although resting PLTs readily stain for the plasma membrane (PM) pools of PI(4,5)P2 and PI4P, just a few activated cells were stained with the established protocol. We show that optimized protocol allows for the visualization of PI(4,5)P2 and PI4P at PM in activated PLTs, which could also be modulated by OCRL and PI4KIIIα inhibitors. We conclude that PI(4,5)P2 and PI4P are more sensitive to lipid extraction by permeabilizing agents in activated than in resting human PLTs, which suggests their different roles during PLT activation.
Collapse
|
8
|
Serial block-face scanning electron microscopy: A provocative technique to define 3-dimensional ultrastructure of microvascular thrombosis. Thromb Res 2020; 196:519-522. [PMID: 33099176 DOI: 10.1016/j.thromres.2020.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/02/2020] [Accepted: 10/07/2020] [Indexed: 01/31/2023]
|
9
|
Andrade SS, Faria AVDS, Girão MJBC, Fuhler GM, Peppelenbosch MP, Ferreira-Halder CV. Biotech-Educated Platelets: Beyond Tissue Regeneration 2.0. Int J Mol Sci 2020; 21:E6061. [PMID: 32842455 PMCID: PMC7503652 DOI: 10.3390/ijms21176061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 11/21/2022] Open
Abstract
The increasing discoveries regarding the biology and functions of platelets in the last decade undoubtedly show that these cells are one of the most biotechnological human cells. This review summarizes new advances in platelet biology, functions, and new concepts of biotech-educated platelets that connect advanced biomimetic science to platelet-based additive manufacturing for tissue regeneration. As highly responsive and secretory cells, platelets could be explored to develop solutions that alter injured microenvironments through platelet-based synthetic biomaterials with instructive extracellular cues for morphogenesis in tissue engineering beyond tissue regeneration 2.0.
Collapse
Affiliation(s)
| | - Alessandra Valéria de Sousa Faria
- Department of Biochemistry and Tissue Biology, University of Campinas, UNICAMP, Campinas, SP 13083-862, Brazil; (A.V.d.S.F.); (C.V.F.-H.)
- Department of Gastroenterology and Hepatology Medical Center Rotterdam, NL-3000 CA Rotterdam, The Netherlands; (G.M.F.); (M.P.P.)
| | | | - Gwenny M. Fuhler
- Department of Gastroenterology and Hepatology Medical Center Rotterdam, NL-3000 CA Rotterdam, The Netherlands; (G.M.F.); (M.P.P.)
| | - Maikel P. Peppelenbosch
- Department of Gastroenterology and Hepatology Medical Center Rotterdam, NL-3000 CA Rotterdam, The Netherlands; (G.M.F.); (M.P.P.)
| | - Carmen V. Ferreira-Halder
- Department of Biochemistry and Tissue Biology, University of Campinas, UNICAMP, Campinas, SP 13083-862, Brazil; (A.V.d.S.F.); (C.V.F.-H.)
| |
Collapse
|
10
|
Pokrovskaya I, Tobin M, Desai R, Aronova MA, Kamykowski JA, Zhang G, Joshi S, Whiteheart SW, Leapman RD, Storrie B. Structural analysis of resting mouse platelets by 3D-EM reveals an unexpected variation in α-granule shape. Platelets 2020; 32:608-617. [PMID: 32815431 DOI: 10.1080/09537104.2020.1799970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mice and mouse platelets are major experimental models for hemostasis and thrombosis; however, important physiological data from this model has received little to no quantitative, 3D ultrastructural analysis. We used state-of-the-art, serial block imaging scanning electron microscopy (SBF-SEM, nominal Z-step size was 35 nm) to image resting platelets from C57BL/6 mice. α-Granules were identified morphologically and rendered in 3D space. The quantitative analysis revealed that mouse α-granules typically had a variable, elongated, rod shape, different from the round/ovoid shape of human α-granules. This variation in length was confirmed qualitatively by higher-resolution, focused ion beam (FIB) SEM at a nominal 5 nm Z-step size. The unexpected α-granule shape raises novel questions regarding α-granule biogenesis and dynamics. Does the variation arise at the level of the megakaryocyte and α-granule biogenesis or from differences in α-granule dynamics and organelle fusion/fission events within circulating platelets? Further quantitative analysis revealed that the two major organelles in circulating platelets, α-granules and mitochondria, displayed a stronger linear relationship between organelle number/volume and platelet size, i.e., a scaling in number and volume to platelet size, than found in human platelets suggestive of a tighter mechanistic regulation of their inclusion during platelet biogenesis. In conclusion, the overall spatial arrangement of organelles within mouse platelets was similar to that of resting human platelets, with mouse α-granules clustered closely together with little space for interdigitation of other organelles.
Collapse
Affiliation(s)
- Irina Pokrovskaya
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Michael Tobin
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH, Bethesda, MD, USA
| | - Rohan Desai
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH, Bethesda, MD, USA
| | - Maria A Aronova
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH, Bethesda, MD, USA
| | - Jeffrey A Kamykowski
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Guofeng Zhang
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH, Bethesda, MD, USA
| | - Smita Joshi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Sidney W Whiteheart
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Richard D Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH, Bethesda, MD, USA
| | - Brian Storrie
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| |
Collapse
|
11
|
Hille L, Lenz M, Vlachos A, Grüning B, Hein L, Neumann FJ, Nührenberg TG, Trenk D. Ultrastructural, transcriptional, and functional differences between human reticulated and non-reticulated platelets. J Thromb Haemost 2020; 18:2034-2046. [PMID: 32428354 DOI: 10.1111/jth.14895] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/22/2020] [Accepted: 05/06/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Reticulated platelets (RP) are the youngest circulating platelets in blood. An increased amount of this subpopulation is associated with higher cardiovascular risk and mortality. OBJECTIVES It is unknown to what extent intrinsic properties of RP contribute to their hyperreactive features. This study is the first providing a multifactorial approach based on ultrastructural, transcriptional, and functional analysis of RP compared to non-RP sorted by flow cytometry. METHODS Reticulated platelets and non-RP were sorted after platelet staining with SYTO 13. Employing transmission electron microscopy, 1089 micrographs were analyzed for platelet size, amounts of intracellular structures, and anatomical surrogates indicating activation. Long and small RNA-sequencing (RNA-seq) were performed for analyzing differential gene expression. Functional analysis of P-selectin-an upregulated mRNA in RP-was performed in healthy subjects and patients on P2Y12 -inhibitors. RESULTS Electron micrographs uncovered distinct ultrastructural differences in RP versus non-RP. Cross sections were 1.9-fold larger in RP (P < .0001). Amounts of α-granules, dense granules, open canalicular system-openings, and mitochondria were increased in RP, which persisted after adjustment for platelet size. Long RNA-seq showed 1212 upregulated transcripts that are predominantly associated to platelet shape change, aggregation, and activation; 1264 mRNAs were downregulated in RP. Small RNA-seq did not reveal any differentially expressed transcripts. Functional analysis displayed higher P-selectin expression as compared to non-RP upon ADP- or TRAP-stimulation. CONCLUSIONS Our results demonstrate that altered intrinsic structural and molecular properties contribute to the hyperreactivity of RP. These properties and an increased amount of RP may account for the association with cardiovascular risk.
Collapse
Affiliation(s)
- Laura Hille
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in Neuromodulation, University of Freiburg, Freiburg, Germany
| | - Björn Grüning
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Lutz Hein
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Franz-Josef Neumann
- Department of Cardiology and Angiology II, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Thomas G Nührenberg
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Angiology II, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| | - Dietmar Trenk
- Department of Cardiology and Angiology II, Clinical Pharmacology, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
| |
Collapse
|
12
|
Tomaiuolo M, Litvinov RI, Weisel JW, Stalker TJ. Use of electron microscopy to study platelets and thrombi. Platelets 2020; 31:580-588. [PMID: 32423268 PMCID: PMC7332414 DOI: 10.1080/09537104.2020.1763939] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 01/23/2023]
Abstract
Electron microscopy has been a valuable tool for the study of platelet biology and thrombosis for more than 70 years. Early studies using conventional transmission and scanning electron microscopy (EM) provided a foundation for our initial understanding of platelet structure and how it changes upon platelet activation. EM approaches have since been utilized to study platelets and thrombi in the context of basic, translational and clinical research, and they are instrumental in the diagnosis of multiple platelet function disorders. In this brief review, we provide a sampling of the many contributions EM based studies have made to the field, including both historical highlights and contemporary applications. We will also discuss exciting new imaging modalities based on EM and their utility for the study of platelets, hemostasis and thrombosis into the future.
Collapse
Affiliation(s)
| | - Rustem I. Litvinov
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - John W. Weisel
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | | |
Collapse
|
13
|
Pokrovskaya ID, Tobin M, Desai R, Joshi S, Kamykowski JA, Zhang G, Aronova MA, Whiteheart SW, Leapman RD, Storrie B. Canalicular system reorganization during mouse platelet activation as revealed by 3D ultrastructural analysis. Platelets 2020; 32:97-104. [PMID: 32000578 DOI: 10.1080/09537104.2020.1719993] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The canalicular system (CS) has been defined as: 1) an inward, invaginated membrane connector that supports entry into and exit from the platelet; 2) a static structure stable during platelet isolation; and 3) the major source of plasma membrane (PM) for surface area expansion during activation. Recent analysis from STEM tomography and serial block face electron microscopy has challenged the relative importance of CS as the route for granule secretion. Here, We used 3D ultrastructural imaging to reexamine the CS in mouse platelets by generating high-resolution 3D reconstructions to test assumptions 2 and 3. Qualitative and quantitative analysis of whole platelet reconstructions, obtained from immediately fixed or washed platelets fixed post-washing, indicated that CS, even in the presence of activation inhibitors, reorganized during platelet isolation to generate a more interconnected network. Further, CS redistribution into the PM at different times, post-activation, appeared to account for only about half the PM expansion seen in thrombin-activated platelets, in vitro, suggesting that CS reorganization is not sufficient to serve as a dominant membrane reservoir for activated platelets. In sum, our analysis highlights the need to revisit past assumptions about the platelet CS to better understand how this membrane system contributes to platelet function.
Collapse
Affiliation(s)
- Irina D Pokrovskaya
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences , Little Rock, AR, USA
| | - Michael Tobin
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH , Bethesda, MD, USA
| | - Rohan Desai
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH , Bethesda, MD, USA
| | - Smita Joshi
- Department of Molecular and Cellular Biochemistry, University of Kentucky , Lexington, Kentucky, USA
| | - Jeffrey A Kamykowski
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences , Little Rock, AR, USA
| | - Guofeng Zhang
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH , Bethesda, MD, USA
| | - Maria A Aronova
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH , Bethesda, MD, USA
| | - Sidney W Whiteheart
- Department of Molecular and Cellular Biochemistry, University of Kentucky , Lexington, Kentucky, USA
| | - Richard D Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, NIH , Bethesda, MD, USA
| | - Brian Storrie
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences , Little Rock, AR, USA
| |
Collapse
|
14
|
Pokrovskaya ID, Yadav S, Rao A, McBride E, Kamykowski JA, Zhang G, Aronova MA, Leapman RD, Storrie B. 3D ultrastructural analysis of α-granule, dense granule, mitochondria, and canalicular system arrangement in resting human platelets. Res Pract Thromb Haemost 2020; 4:72-85. [PMID: 31989087 PMCID: PMC6971324 DOI: 10.1002/rth2.12260] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/29/2019] [Accepted: 09/04/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND State-of-the-art 3-dimensional (3D) electron microscopy approaches provide a new standard for the visualization of human platelet ultrastructure. Application of these approaches to platelets rapidly fixed prior to purification to minimize activation should provide new insights into resting platelet ultrastructure. OBJECTIVES Our goal was to determine the 3D organization of α-granules, dense granules, mitochondria, and canalicular system in resting human platelets and map their spatial relationships. METHODS We used serial block face-scanning electron microscopy images to render the 3D ultrastructure of α-granules, dense granules, mitochondria, canalicular system, and plasma membrane for 30 human platelets, 10 each from 3 donors. α-Granule compositional data were assessed by sequential, serial section cryo-immunogold electron microscopy and by immunofluorescence (structured illumination microscopy). RESULTS AND CONCLUSIONS α-Granule number correlated linearly with platelet size, while dense granule and mitochondria number had little correlation with platelet size. For all subcellular compartments, individual organelle parameters varied considerably and organelle volume fraction had little correlation with platelet size. Three-dimensional data from 30 platelets indicated only limited spatial intermixing of the different organelle classes. Interestingly, almost 70% of α-granules came within ≤35 nm of each other, a distance associated in other cell systems with protein-mediated contact sites. Size and shape analysis of the 1488 α-granules analyzed revealed no more variation than that expected for a Gaussian distribution. Protein distribution data indicated that all α-granules likely contained the same major set of proteins, albeit at varying amounts and varying distribution within the granule matrix.
Collapse
Affiliation(s)
- Irina D. Pokrovskaya
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Shilpi Yadav
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Amith Rao
- Laboratory of Cellular Imaging and Macromolecular BiophysicsNIBIBNIHBethesdaMDUSA
| | - Emma McBride
- Laboratory of Cellular Imaging and Macromolecular BiophysicsNIBIBNIHBethesdaMDUSA
| | - Jeffrey A. Kamykowski
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Guofeng Zhang
- Laboratory of Cellular Imaging and Macromolecular BiophysicsNIBIBNIHBethesdaMDUSA
| | - Maria A. Aronova
- Laboratory of Cellular Imaging and Macromolecular BiophysicsNIBIBNIHBethesdaMDUSA
| | - Richard D. Leapman
- Laboratory of Cellular Imaging and Macromolecular BiophysicsNIBIBNIHBethesdaMDUSA
| | - Brian Storrie
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| |
Collapse
|
15
|
|
16
|
Impact of Escherichia coli K12 and O18:K1 on human platelets: Differential effects on platelet activation, RNAs and proteins. Sci Rep 2018; 8:16145. [PMID: 30385858 PMCID: PMC6212526 DOI: 10.1038/s41598-018-34473-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/08/2018] [Indexed: 12/12/2022] Open
Abstract
Blood platelets can interact with bacteria, possibly leading to platelet activation, cytokine and microparticle release and immune signalling. Besides, bacteria can also affect the platelet RNA content. We investigated the impact of non-pathogenic K12 and pathogenic O18:K1 Escherichia (E.) coli strains on platelet activation, RNA expression patterns, and selected proteins. Depending on bacteria concentration, contact of platelets with E. coli K12 lead to an increase of P-selectin (24–51.3%), CD63 (15.9–24.3%), PAC-1 (3.8–14.9%) and bound fibrinogen (22.4–39%) on the surface. E. coli O18:K1 did not affect these markers. Sequencing analysis of total RNA showed that E. coli K12 caused a significant concentration change of 103 spliced mRNAs, of which 74 decreased. For the RNAs of HMBS (logFC = +5.73), ATP2C1 (logFC = −3.13) and LRCH4 (logFC = −4.07) changes were detectable by thromboSeq and Tuxedo pipelines. By Western blot we observed the conversion of HMBS protein from a 47 kDA to 40 kDa product by E. coli K12, O18:K1 and by purified lipopolysaccharide. While ATP2C1 protein was released from platelets, E. coli either reduced the secretion or broke down the released protein making it undetectable by antibodies. Our results demonstrate that different E. coli strains influence activation, RNA and protein levels differently which may affect platelet-bacteria crosstalk.
Collapse
|
17
|
Abstract
Our understanding of fundamental biological processes within platelets is continually evolving. A critical feature of platelet biology relates to the intricate uptake, packaging and release of bioactive cargo from storage vesicles, essential in mediating a range of classical (haemostasis/thrombosis) and non-classical (regeneration/inflammation/metastasis) roles platelets assume. Pivotal to the molecular control of these vesicle trafficking events are the small GTPases of the Ras superfamily, which function as spatially distinct, molecular switches controlling essential cellular processes. Herein, we specifically focus on members of the Rab, Arf and Ras subfamilies, which comprise over 130 members and platelet proteomic datasets suggest that more than half of these are expressed in human platelets. We provide an update of current literature relating to trafficking roles for these GTPases in platelets, particularly regarding endocytic and exocytic events, but also vesicle biogenesis and provide speculative argument for roles that other related GTPases and regulatory proteins may adopt in platelets. Advances in our understanding of small GTPase function in the anucleate platelet has been hampered by the lack of specific molecular tools, but it is anticipated that this will be greatly accelerated in the years ahead and will be crucial to the identification of novel therapeutic targets controlling different platelet processes.
Collapse
Affiliation(s)
- Tony G Walsh
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Yong Li
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Andreas Wersäll
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| | - Alastair W Poole
- a From the School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building , University of Bristol , Bristol , UK
| |
Collapse
|
18
|
Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography. J Struct Biol 2018; 202:216-228. [PMID: 29408702 DOI: 10.1016/j.jsb.2018.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/26/2018] [Accepted: 01/30/2018] [Indexed: 11/22/2022]
Abstract
Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach.
Collapse
|
19
|
Abstract
PURPOSE OF REVIEW Although platelet endocytosis has been recognized in granule cargo loading and the trafficking of several platelet surface receptors, its acute physiological relevance is poorly understood as is its mechanism. The present review discusses the current understanding of platelet endocytosis and its implications for platelet function. RECENT FINDINGS Recent studies are beginning to identify and define the proteins that mediate platelet endocytosis. These studies have shown that platelets contain different endosomal compartments and may use multiple endocytic routes to take in circulating molecules and surface proteins. The studies have also shown that platelet endocytosis is involved in several aspects of platelet function such as signaling, spreading, and granule cargo loading. SUMMARY Mechanistic studies of platelet endocytosis have shown it to be not only involved in granule cargo loading but also in various other platelet functions important for hemostasis and beyond.
Collapse
|
20
|
Platelet mitochondrial dysfunction and the correlation with human diseases. Biochem Soc Trans 2017; 45:1213-1223. [PMID: 29054925 DOI: 10.1042/bst20170291] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/10/2017] [Accepted: 09/14/2017] [Indexed: 12/20/2022]
Abstract
The platelet is considered as an accessible and valuable tool to study mitochondrial function, owing to its greater content of fully functional mitochondria compared with other metabolically active organelles. Different lines of studies have demonstrated that mitochondria in platelets have function far more than thrombogenesis regulation, and beyond hemostasis, platelet mitochondrial dysfunction has also been used for studying mitochondrial-related diseases. In this review, the interplay between platelet mitochondrial dysfunction and oxidative stress, mitochondrial DNA lesions, electron transfer chain impairments, mitochondrial apoptosis and mitophagy has been outlined. Meanwhile, considerable efforts have been made towards understanding the role of platelet mitochondrial dysfunction in human diseases, such as diabetes mellitus, sepsis and neurodegenerative disorders. Alongside this, we have also articulated our perspectives on the development of potential biomarkers of platelet mitochondrial dysfunction in mitochondrial-related diseases.
Collapse
|
21
|
Yadav S, Storrie B. The cellular basis of platelet secretion: Emerging structure/function relationships. Platelets 2017; 28:108-118. [PMID: 28010140 PMCID: PMC5627609 DOI: 10.1080/09537104.2016.1257786] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 12/27/2022]
Abstract
Platelet activation has long been known to be accompanied by secretion from at least three types of compartments. These include dense granules, the major source of small molecules; α-granules, the major protein storage organelle; and lysosomes, the site of acid hydrolase storage. Despite ~60 years of research, there are still many unanswered questions about the cell biology of platelet secretion: for example, how are these secretory organelles organized to support cargo release and what are the key routes of cargo release, granule to plasma membrane or granule to canalicular system. Moreover, in recent years, increasing evidence points to the platelet being organized for secretion of the contents from other organelles, namely the dense tubular system (endoplasmic reticulum) and the Golgi apparatus. Conceivably, protein secretion is a widespread property of the platelet and its organelles. In this review, we concentrate on the cell biology of the α-granule and its structure/function relationships. We both review the literature and discuss the wide array of 3-dimensional, high-resolution structural approaches that have emerged in the last few years. These have begun to reveal new and unanticipated outcomes and some of these are discussed. We are hopeful that the next several years will bring rapid advances to this field that will resolve past controversies and be clinically relevant.
Collapse
Affiliation(s)
- Shilpi Yadav
- a Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Brian Storrie
- a Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| |
Collapse
|