A comprehensive review on Eryptosis

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa: E Pretorius.http://www.karger.com/cpbam2017Physiolog

A comprehensive review on Eryptosis

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa: E Pretorius.http://www.karger.com/cpbam2017Physiolog

A comprehensive review on Eryptosis

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa: E Pretorius.http://www.karger.com/cpbam2017Physiolog

A comprehensive review on Eryptosis

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa: E Pretorius.http://www.karger.com/cpbam2017Physiolog

A comprehensive review on Eryptosis

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa: E Pretorius.http://www.karger.com/cpbam2017Physiolog

An ultrastructural analysis of platelets, erythrocytes, white blood cells, and fibrin network in systemic lupus erythematosus

The study suggests that patients with systemic lupus erythematosus (SLE) present with distinct inflammatory ultrastructural changes such as platelets blebbing, generation of platelet-derived microparticles, spontaneous formation of massive fibrin network and fusion of the erythrocytes membranes. Lupoid platelets actively interact with other inflammatory cells, particularly with white blood cells (WBCs), and the massive fibrin network facilitates such an interaction. It is possible that the concerted actions of platelets, erythrocytes and WBC, caught in the inflammatory fibrin network, predispose to pro-thrombotic states in patients with SLE.http://link.springer.com/journal/296am201

Comparing platelet function and ultrastructure in smoking and thrombo-embolic ischemic stroke

Stroke is serious neurological disease and is a major cause of death as well as disability throughout the globe. Stroke has a complex pathophysiology that involves inflammatory pathways, excitotoxicity mechanisms, oxidative damage, apoptosis, ionic imbalances, angiogenesis and neuroprotection. 85% of strokes are ischemic and occurs when a cerebral vessel, or any vessel supplying the brain, narrows or loses pressure resulting in subsequent brain ischemia and infarction downstream to the site of obstruction depriving tissues of vital oxygen and nutrients. This may be caused by either atherosclerotic thrombi or distant emboli defined as a mass of clotted blood or other material. It is estimated that over a billion people currently smoke cigarettes or use other tobacco products, seeing as smoking is a major risk factor for stroke this is of major concern. Platelets are hematopoietic cells produced by bone marrow megakaryocytes. Platelets play a role in the development of ischemic stroke primarily by means of their participation in the formation of thromboemboli, the presence of abnormal platelet function may predispose patients to a pro-thrombotic, pro-inflammatory state. The reorganization of the cytoskeleton in platelets is an important factor in the complex mechanisms found in thrombosis and haemostasis. The platelet membrane contains a large number of receptors which specifically bind agonists that stimulate the physiological platelet response. Oxidative stress is one of the mechanisms involved in the neuronal damage of stroke. Oxidative stress is a state of imbalance between free radical production, in particular, reactive oxygen species (ROS), and the ability of the organism to neutralize them, leading to progressive oxidative damage. Smoking is known to result in the generation of various free radicals. Flow cytometric analysis of the platelets of thrombo-embolic ischemic stroke patients and smokers revealed that the membranes of the two groups were altered in some form as well as an increased activation in both groups when compared to healthy individuals. Superoxide levels in the platelets were higher in smokers when compared to stroke patients, while hydrogen peroxide levels were elevated in the platelets of both groups. Superoxide was elevated in the whole blood samples of both groups. The production and subsequent reactions of reactive oxygen species appear to be influential in stroke and smoking and may likely be a crucial factor in the development of a pro-thrombotic, pro-inflammatory state which may prove to be a hallmark in the pathophysiology of stroke and smoking. Confocal microscopy and Scanning electron microscopy showed that platelets of stroke patients and smokers appear to be more activated and more prone to form tight clots. Furthermore an increased amount of superoxide is present in the platelets of stroke patients and smokers, specifically in the centre of clots. This may be an indication that once platelets have aggregated and started to fuse together, the mitochondria are expelled from the platelets and “trapped” within the clot. Atomic force microscopy also indicated both the stroke patients and smoker‟s platelets appear to be in a more activated state than the control group. Here it is apparent that some form of cytoskeletal rearrangement takes place to a more severe extent in the stroke group than in the smokers. Necrosis may be present in the platelets of stroke patients while neither apoptosis nor necrosis can be identified in the platelets of smokers however some form of membrane alteration is likely present. All the techniques used showed an increase in platelet activation in stroke patients and smokers, necrotic platelets may be present in the stroke patients while the platelet membrane of smokers seems to be altered. ROS is present and alters the platelet function of smokers and stroke patients in some way. It appears as if thrombo-embolic ischemic stroke patients and smokers‟ platelets have similar trends in activation but the processes involved to achieve this differ as there are structural differences present. These differences may prove a useful tool to further understand the pathophysiology behind thrombo-embolic ischemic stroke as well as to discover new therapeutic pathways.Dissertation (MSc)--University of Pretoria, 2013.gm2014PhysiologyUnrestricte

Comparison of platelet ultrastructure and elastic properties in thrombo-embolic ischemic stroke and smoking using atomic force and scanning electron microscopy.

Thrombo-embolic ischemic stroke is a serious and debilitating disease, and it remains the second most common cause of death worldwide. Tobacco smoke exposure continues to be responsible for preventable deaths around the world, and is a major risk factor for stroke. Platelets play a fundamental role in clotting, and their pathophysiological functioning is present in smokers and stroke patients, resulting in a pro-thrombotic state. In the current manuscript, atomic force and scanning electron microscopy were used to compare the platelets of smokers, stroke patients and healthy individuals. Results showed that the elastic modulus of stroke platelets is decreased by up to 40%, whereas there is an elasticity decrease of up to 20% in smokers' platelets. This indicates a biophysical alteration of the platelets. Ultrastructurally, both the stroke patients and smokers' platelets are more activated than the healthy control group, with prominent cytoskeletal rearrangement involved; but to a more severe extent in the stroke group than in the smokers. Importantly, this is a confirmation of the extent of smoking as risk factor for stroke. We conclude by suggesting that the combined AFM and SEM analyses of platelets might give valuable information about the disease status of patients. Efficacy of treatment regimes on the integrity, cell shape, roughness and health status of platelets may be tracked, as this cell's health status is crucial in the over-activated coagulation system of conditions like stroke

Flow cytometric analysis of platelets type 2 diabetes mellitus reveals ‘angry’ platelets

BACKGROUND : The function of platelets have extended way beyond the horizon of haemostasis and thrombosis, and are recognised as active participants in vascular inflammation, as well as in prothrombotic complications of cardiovascular diseases. We describe and compare platelet function in type II diabetes (with and without cardiovascular manifestation) and healthy individuals using scanning electron microscopy and flow cytometry. METHODS : Thirty subjects were recruited per group and informed consent was obtained from all participants. Diabetic patients were recruited from the diabetic clinic of the Steve Biko Academic Hospital (South Africa). Blood samples were drawn from all participants so that platelet specific antigens were analyzed in citrated whole blood. The platelet parameters used in the study were platelet identifiers (CD41 and CD42) and markers of platelet activation (CD62 and CD63). RESULTS : Results show that, compared to healthy individuals, both diabetic groups showed a significant difference in both platelet identifiers (CD41-PE, CD42b-PE) as well as markers indicating platelet activation (CD62P-PE and CD63-PE). INTERPRETATION : The flow cytometric data shows that the platelet surface receptors and platelet activation are statistically elevated. This is suggestive of enhanced platelet activation and it appears as if platelets are displaying ‘angry’ behaviour. The lysosomal granules may play a significant role in diabetes with cardiovascular complications. These results were confirmed by ultrastructural analysis.The National Research Foundation (NRF) (South Africa) (Unique Grant No: 92709) and the Medical Research Council (MRC) (South Africa).http://www.cardiab.comam2016Physiolog