Adverse effects of delta-9-tetrahydrocannabinol on sickle red blood cells.

THC triggers a pronounced entry of Ca , which may be deleterious, into sickle cell red blood cells via activation of the TRPV2 channel.

Dual action of Dooku1 on PIEZO1 channel in human red blood cells.

PIEZO1 is a mechanosensitive non-selective cation channel, present in many cell types including Red Blood Cells (RBCs). Together with the Gárdos channel, PIEZO1 forms in RBCs a tandem that participates in the rapid adjustment of the cell volume. The pharmacology allowing functional studies of the roles of PIEZO1 has only recently been developed, with Yoda1 as a widely used PIEZO1 agonist.

Effect of an augmented reality active video game for gait training in children with cerebral palsy following single-event multilevel surgery: protocol for a randomised controlled trial.

Introduction: In paediatric rehabilitation, fun and motivation are also critical keys to successful therapy. A variety of interventions have shown positive effects, high level of interest, compliance and engagement with active video game (AVG).This seems to be an interesting approach for the postoperative gait rehabilitation of children with cerebral palsy (CP).

Visual Feedback in Augmented Reality to Walk at Predefined Speed Cross-Sectional Study Including Children With Cerebral Palsy.

In an augmented reality environment, the range of possible real-time visual feedback is extensive. This study aimed to compare the impact of six scenarios in augmented reality combining four visual feedback characteristics on achieving a target walking speed. The six scenarios have been developed for Microsoft Hololens augmented reality headset.

The Chloride Conductance Inhibitor NS3623 Enhances the Activity of a Non-selective Cation Channel in Hyperpolarizing Conditions.

Handbooks of physiology state that the strategy adopted by red blood cells (RBCs) to preserve cell volume is to maintain membrane permeability for cations at its minimum. However, enhanced cation permeability can be measured and observed in specific physiological and pathophysiological situations such as senescence, storage at low temperature, sickle cell anemia and many other genetic defects affecting transporters, membrane or cytoskeletal proteins. Among cation pathways, cation channels are able to dissipate rapidly the gradients that are built and maintained by the sodium and calcium pumps.

Validity of Hololens Augmented Reality Head Mounted Display for Measuring Gait Parameters in Healthy Adults and Children with Cerebral Palsy.

Serious games are a promising approach to improve gait rehabilitation for people with gait disorders. Combined with wearable augmented reality headset, serious games for gait rehabilitation in a clinical setting can be envisaged, allowing to evolve in a real environment and provide fun and feedback to enhance patient's motivation. This requires a method to obtain accurate information on the spatiotemporal gait parameters of the playing patient.

Gardos channelopathy: functional analysis of a novel KCNN4 variant.

We show that the novel variant p.S314P is a gain-of-function mutation but is less severe than the previously reported p.R352H variant.

Plasmodium falciparum sexual parasites regulate infected erythrocyte permeability.

To ensure the transport of nutrients necessary for their survival, Plasmodium falciparum parasites increase erythrocyte permeability to diverse solutes. These new permeation pathways (NPPs) have been extensively characterized in the pathogenic asexual parasite stages, however the existence of NPPs has never been investigated in gametocytes, the sexual stages responsible for transmission to mosquitoes. Here, we show that NPPs are still active in erythrocytes infected with immature gametocytes and that this activity declines along gametocyte maturation.

Induction of ATP Release, PPIX Transport, and Cholesterol Uptake by Human Red Blood Cells Using a New Family of TSPO Ligands.

Two main isoforms of the Translocator Protein (TSPO) have been identified. TSPO1 is ubiquitous and is mainly present at the outer mitochondrial membrane of most eukaryotic cells, whereas, TSPO2 is specific to the erythroid lineage, located at the plasma membrane, the nucleus, and the endoplasmic reticulum. The design of specific tools is necessary to determine the molecular associations and functions of TSPO, which remain controversial nowadays.

Plasmodiumfalciparum infection induces dynamic changes in the erythrocyte phospho-proteome.

The phosphorylation status of red blood cell proteins is strongly altered during the infection by the malaria parasite Plasmodium falciparum. We identify the key phosphorylation events that occur in the erythrocyte membrane and cytoskeleton during infection, by a comparative analysis of global phospho-proteome screens between infected (obtained at schizont stage) and uninfected RBCs. The meta-analysis of reported mass spectrometry studies revealed a novel compendium of 495 phosphorylation sites in 182 human proteins with regulatory roles in red cell morphology and stability, with about 25% of these sites specific to infected cells.

A vacuolar iron-transporter homologue acts as a detoxifier in Plasmodium.

Iron is an essential micronutrient but is also highly toxic. In yeast and plant cells, a key detoxifying mechanism involves iron sequestration into intracellular storage compartments, mediated by members of the vacuolar iron-transporter (VIT) family of proteins. Here we study the VIT homologue from the malaria parasites Plasmodium falciparum (PfVIT) and Plasmodium berghei (PbVIT).

Mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, enlarge the parasite's food vacuole and alter drug sensitivities.

Mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, are the major determinant of chloroquine resistance in this lethal human malaria parasite. Here, we describe P. falciparum lines subjected to selection by amantadine or blasticidin that carry PfCRT mutations (C101F or L272F), causing the development of enlarged food vacuoles.

Red cell investigations: art and artefacts.

Red blood cell research is important for both, the clinical haematology, such as transfusion medicine or anaemia investigations, and the basic research fields like exploring general membrane physiology or rheology. Investigations of red blood cells include a wide spectrum of methodologies ranging from population measurements with a billion cells evaluated simultaneously to single-cell approaches. All methods have a potential for pitfalls, and the comparison of data achieved by different technical approaches requires a consistent set of standards.

Plasmodium falciparum STEVOR proteins impact erythrocyte mechanical properties.

Infection of erythrocytes with the human malaria parasite, Plasmodium falciparum, results in dramatic changes to the host cell structure and morphology. The predicted functional localization of the STEVOR proteins at the erythrocyte surface suggests that they may be involved in parasite-induced modifications of the erythrocyte membrane during parasite development. To address the biologic function of STEVOR proteins, we subjected a panel of stevor transgenic parasites and wild-type clonal lines exhibiting different expression levels for stevor genes to functional assays exploring parasite-induced modifications of the erythrocyte membrane.

Erythrocyte peripheral type benzodiazepine receptor/voltage-dependent anion channels are upregulated by Plasmodium falciparum.

Plasmodium falciparum relies on anion channels activated in the erythrocyte membrane to ensure the transport of nutrients and waste products necessary for its replication and survival after invasion. The molecular identity of these anion channels, termed "new permeability pathways" is unknown, but their currents correspond to up-regulation of endogenous channels displaying complex gating and kinetics similar to those of ligand-gated channels. This report demonstrates that a peripheral-type benzodiazepine receptor, including the voltage dependent anion channel, is present in the human erythrocyte membrane.

Ion channels in human red blood cell membrane: actors or relics?

During the past three decades, electrophysiological studies revealed that human red blood cell membrane is endowed with a large variety of ion channels. The physiological role of these channels, if any, remains unclear; they do not participate in red cell homeostasis which is rather based on the almost total absence of cationic permeability and minute anionic conductance. They seem to be inactive in the "resting cell.

Anion conductance of the human red cell is carried by a maxi-anion channel.

Historically, the anion transport through the human red cell membrane has been perceived to be mediated by Band 3, in the two-component concept with the large electroneutral anion exchange accompanied by the conductance proper, which dominated the total membrane conductance. The status of anion channels proper has never been clarified, and the informations obtained by different groups of electrophysiologists are rather badly matched. This study, using the cell-attached configuration of the patch-clamp technique, rationalizes and explains earlier confusing results by demonstrating that the diversity of anionic channel activities recorded in human erythrocytes corresponds to different kinetic modalities of a unique type of maxi-anion channel with multiple conductance levels and probably multiple gating properties and pharmacology, depending on conditions.

Local membrane deformations activate Ca2+-dependent K+ and anionic currents in intact human red blood cells.

Background: The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such flow, as well as the local membrane deformations generated in certain pathological conditions, such as sickle cell anemia, have been shown to increase membrane permeability, based largely on experimentation with red cell suspensions. We attempted here the first measurements of membrane currents activated by a local and controlled membrane deformation in single red blood cells under on-cell patch clamp to define the nature of the stretch-activated currents.

Effects of elevated intracellular calcium on the osmotic fragility of human red blood cells.

High throughput methodologies that measure the distribution of osmotic fragilities in red blood cell populations have enabled the investigation of dynamic changes in red cell homeostasis and membrane permeability in health and disease. The common assumption in the interpretation of dynamic changes in osmotic fragility curves is that left or right shifts reflect a decreased or increased hydration state of the cells, respectively, allowing direct inferences on membrane transport from osmotic fragility measurements. However, the assumed correlation between shifts in osmotic fragility and hydration state has never been directly explored, and may prove invalid in certain conditions.

Anion channels in Plasmodium-falciparum-infected erythrocytes and protein kinase A.

By replicating within red blood cells, malaria parasites are largely hidden from immune recognition; however, in the cells, nutrients are limiting and hazardous metabolic end products can rapidly accumulate. Therefore, to survive within erythrocytes, parasites alter the permeability of the host plasma membrane, either by upregulating existing transporters or by creating new permeation pathways. Recent electrophysiological studies of Plasmodium-infected erythrocytes have demonstrated that membrane permeability is mediated by transmembrane transport through ion channels in the infected erythrocyte.

Further characterization of cation channels present in the chicken red blood cell membrane.

In this paper, we provide an update on cation channels in nucleated chicken erythrocytes. Patch-clamp techniques were used to further characterize the two different types of cation channels present in the membrane of chicken red blood. In the whole-cell mode, with Ringer in the bath and internal K+ saline in the pipette solution, the membrane conductance was generated by cationic currents, since the reversal potential was shifted toward cations equilibrium when the impermeant cation NMDG was substituted to small cations.

Plasmodium falciparum regulatory subunit of cAMP-dependent PKA and anion channel conductance.

Malaria symptoms occur during Plasmodium falciparum development into red blood cells. During this process, the parasites make substantial modifications to the host cell in order to facilitate nutrient uptake and aid in parasite metabolism. One significant alteration that is required for parasite development is the establishment of an anion channel, as part of the establishment of New Permeation Pathways (NPPs) in the red blood cell plasma membrane, and we have shown previously that one channel can be activated in uninfected cells by exogenous protein kinase A.