Is the flavin-deficient red blood cell common in Maremma, Italy, an important defense against malaria in this area?

There is a high prevalence of a familial flavin-deficient red blood cell in Ferrara province in the Po delta in northern Italy, believed to have been selected for by malaria which was endemic from the 12th century. In the present study, activities of FAD-dependent red-cell glutathione reductase (EGR) in the Grosseto area of Maremma on the west coast of Italy where malaria was endemic from 300 B.C. are compared both with activities in the Ferrara area and with activities where there was no history of endemic malaria--in the Florence area and in London in people of Anglo-Saxon origin. EGR activities were similar in Grosseto and Ferrara and were significantly lower than in Florence and London. As previously found in Ferrara, low EGR activity in Grosseto was shown to be unrelated to low dietary riboflavin intake. These findings in Grosseto, suggesting selection by malaria, are particularly interesting because, unlike the situation in Ferrara and most other malarial areas, the prevalence of thalassemia and glucose-6-phosphate dehydrogenase deficiency is very low, and they do not appear to have been selected for in Maremma. It is possible that a flavin-deficient red cell, known to inhibit growth of the malaria parasite, was an important protecting factor in the population of this area over the centuries.     

Hawthorn special extract WS? 1442 increases red blood cell NO-formation without altering red blood cell deformability

WS(?) 1442 is a special extract of hawthorn leaves with flowers used for the treatment of mild cardiac failure. The activation of endothelial nitric oxide synthase (eNOS) has been shown to contribute to its vasodilating properties. Quite recently it has been demonstrated that red blood cells (RBCs) express a functional NO-synthase (rbcNOS) and rbcNOS activation has been associated with increased RBC deformability. The aim of the present study was to determine whether WS(?) 1442 is able to activate rbcNOS, to induce NO-formation in RBC and to alter RBC-deformability. Blood from healthy volunteers was incubated with WS(?) 1442 (25-100 μg/ml) for up to 30 min. RbcNOS activation was detected by immunohistochemical staining of phosphorylated rbcNOS and NO-formation was examined by diaminofluorescein (DAF) fluorescence. RBC deformability was measured by a laser assisted optical rotational cell analyzer. Serine 1177 of RbcNOS (rbcNOS Ser(1177)) was time- and concentration-dependently phosphorylated by WS(?) 1442. Rates of rbcNOS Ser(1177) phosphorylation were up to 149% higher in RBCs treated with WS(?) 1442 in comparison to control (DMSO 0.05%). WS(?) 1442 induced a time-dependent increase in NO-formation in RBCs which reached its maximum after 5 min. An increase in shear stress (0.3-50 Pa) caused an increase in RBC deformability. WS(?) 1442 did not change either basal or maximal RBC-deformability or shear stress sensitivity of RBC at normoxia. CONCLUSION: WS(?) 1442 activates rbcNOS and causes NO-formation in RBCs. WS(?) 1442-dependent NO-formation however does not affect RBC-deformability at normoxia.     

Tethering,evagination, and vesiculation via cell–cell interactions in microvascular flow

Biomechanics and Modeling in Mechanobiology - Vesiculation is a ubiquitous process undergone by most cell types and serves a variety of vital cell functions; vesiculation from erythrocytes, in...     

Motile systems in malaria merozoites: how is the red blood cell invaded?

The ability of the malaria parasite to invade erythrocytes is central to the disease process, but is not thoroughly understood. In particular, little attention has been paid to the motor systems driving invasion. Here, Jennifer Pinder, Ruth Fowler and colleagues review motility in the merozoite. The components of an actomyosin motor are present, including a novel unconventional class XIV myosin, now called Pfmyo-A, which, because of its time of synthesis and location, is likely to generate the force required for invasion. In addition, there is a subpellicular microtubule assemblage in falciparum merozoites, the f-MAST, the integrity of which is necessary for invasion.     

How does blood cell concentration modulate cardiovascular parameters in developing zebrafish (Danio rerio)?

Blood flow and shear forces are considered to be important parameters possibly stimulating angiogenesis or cardiovascular remodeling. The main objective of this study was to test the hypothesis that a significant reduction in shear forces as a consequence of a significant isovolemic anemia induced by microsurgical techniques during early larval development of the zebrafish might induce a compensatory stimulation of erythropoiesis and/or induce a modification of cardiac activity or even the formation of the heart and may influence the shaping of the vascular bed. Blood from 2 day old zebrafish larvae was withdrawn and replaced by zebrafish Ringer's solution, so that the blood cell concentration was reduced by at least 75%. At 5 days post fertilization (dpf) a partial recovery in blood cell concentration was observed and reached a value of 814.55+/-85.42 cells/nL, while in control animals blood cell concentration amounted to 1856.00+/-131.59 cells/nL. At 7 dpf the value of blood cell concentration was 1023.89+/-95.75 cells/nL versus 1701.54+/-146.03 cells/nL in control animals. Compared to control animals, heart rate and cardiac output were significantly reduced in anemic animals and alterations in the formation of the vascular bed were also observed. A significant decrease in the end-diastolic volume suggested that ventricular volume was reduced. Thus, within a few days zebrafish larvae were nearly able to compensate for an isovolemic anemia by an enhanced erythropoiesis. However, several changes in cardiovascular system indicated that phenotypic plasticity is established even at an early developmental stage.     

Where does blood go? Prospective observational study of red cell transfusion in north England

ObjectiveTo collect population based information on transfusion of red blood cells.DesignProspective observational study over 28 days.SettingHospital blood banks in the north of England (population 2.9 million).ParticipantsAll patients who received a red cell transfusion during the study period. Data completed by hospital blood bank staff.ResultsThe destination of 9848 units was recorded (97% of expected blood use). In total 9774 units were transfused: 5047 (51.6%) units were given to medical patients, 3982 (40.7%) to surgical patients, and 612 (6.3%) to obstetric and gynaecology patients. Nearly half (49.3%) of all blood is given to female recipients, and the mean age of recipients of individual units was 62.7 years. The most common surgical indications for transfusion were total hip replacement (4.6% of all blood transfused) and coronary artery bypass grafting (4.1%). Haematological disorders accounted for 15.5% of use. Overall use was 4274 units per 100 000 population per year.ConclusionIn the north east of England more than half of red cell units are transfused for medical indications. Demand for red cell transfusion increases with age. With anticipated changes in the age structure of the population the demand for blood will increase by 4.9% by 2008.

What is already known on this topic

There have been no systematic population based surveys on use of red cells in the United KingdomStudies in France and the United States have shown that more than half of transfused red cells go to surgical patients

What this study adds

In the north of England over half of red cells are given for medical indicationsRates of red cell transfusion rise steeply with advancing ageSmall increases in the number of elderly people will have large effects on demand     

α-catenin,vinculin, and F-actin in strengthening E-cadherin cell–cell adhesions and mechanosensing

Classical cadherins play a crucial role in establishing intercellular adhesion, regulating cortical tension, and maintaining mechanical coupling between cells. The mechanosensitive regulation of intercellular adhesion strengthening depends on the recruitment of adhesion complexes at adhesion sites and their anchoring to the actin cytoskeleton. Thus, the molecular mechanisms coupling cadherin-associated complexes to the actin cytoskeleton are actively being studied, with a particular focus on α-catenin and vinculin. We have recently addressed the role of these proteins by analyzing the consequences of their depletion and the expression of α-catenin mutants in the formation and strengthening of cadherin-mediated adhesions. We have used the dual pipette assay to measure the forces required to separate cell doublets formed in suspension. In this commentary, we briefly summarize the current knowledge on the role of α-catenin and vinculin in cadherin-actin cytoskeletal interactions. These data shed light on the tension-dependent contribution of α-catenin and vinculin in a mechanoresponsive complex that promotes the connection between cadherin and the actin cytoskeleton and their requirement in the development of adhesion strengthening.     

Ectoplasm, ghost in the R cell machine?

Drosophila photoreceptors (R cells) are an extreme instance of sensory membrane amplification via apical microvilli, a widely deployed and deeply conserved operation of polarized epithelial cells. Developmental rotation of R cell apices aligns rhabdomere microvilli across the optical axis and enables enormous membrane expansion in a new, proximal distal dimension. R cell ectoplasm, the specialized cortical cytoplasm abutting the rhabdomere is likewise enormously amplified. Ectoplasm is dominated by the actin-rich terminal web, a conserved operational domain of the ancient vesicle-transport motor, Myosin V. R cells harness Myosin V to move two distinct cargoes, the biosynthetic traffic that builds the rhabdomere during development, and the migration of pigment granules that mediates the adaptive "longitudinal pupil" in adults, using two distinct Rab proteins. Ectoplasm further shapes a distinct cortical endosome compartment, the subrhabdomeral cisterna (SRC), vital to normal cell function. Reticulon, a protein that promotes endomembrane curvature, marks the SRC. R cell visual arrestin 2 (Arr2) is predominantly cytoplasmic in dark-adapted photoreceptors but on illumination it translocates to the rhabdomere, where it quenches ongoing photosignaling by binding to activated metarhodopsin. Arr2 translocation is "powered" by diffusion; a motor is not required to move Arr2 and ectoplasm does not obstruct its rapid diffusion to the rhabdomere.     

Seasonal variation in vitamin D₃ levels is paralleled by changes in the peripheral blood human T cell compartment

It is well-recognized that vitamin D₃ has immune-modulatory properties and that the variation in ultraviolet (UV) exposure affects vitamin D₃ status. Here, we investigated if and to what extent seasonality of vitamin D₃ levels are associated with changes in T cell numbers and phenotypes. Every three months during the course of the entire year, human PBMC and whole blood from 15 healthy subjects were sampled and analyzed using flow cytometry. We observed that elevated serum 25(OH)D₃ and 1,25(OH)₂D₃ levels in summer were associated with a higher number of peripheral CD4⁺ and CD8⁺ T cells. In addition, an increase in naïve CD4⁺CD45RA⁺ T cells with a reciprocal drop in memory CD4⁺CD45RO⁺ T cells was observed. The increase in CD4⁺CD45RA⁺ T cell count was a result of heightened proliferative capacity rather than recent thymic emigration of T cells. The percentage of Treg dropped in summer, but not the absolute Treg numbers. Notably, in the Treg population, the levels of forkhead box protein 3 (Foxp3) expression were increased in summer. Skin, gut and lymphoid tissue homing potential was increased during summer as well, exemplified by increased CCR4, CCR6, CLA, CCR9 and CCR7 levels. Also, in summer, CD4⁺ and CD8⁺ T cells revealed a reduced capacity to produce pro-inflammatory cytokines. In conclusion, seasonal variation in vitamin D₃ status in vivo throughout the year is associated with changes in the human peripheral T cell compartment and may as such explain some of the seasonal variation in immune status which has been observed previously. Given that the current observations are limited to healthy adult males, larger population-based studies would be useful to validate these findings.     

Sickle cell anemia,sickle cell β-thalassemia,and thalassemia major in Albania: characterization of mutations

We have analyzed the hemoglobin abnormalities in nearly 50 Albanian patients with a significant hemoglobinopathy and included 37 relatives in this study. Sickle cell anemia (SS) is a common disorder; all 15 sickle cell anemia patients had the complications expected for this disease. The ^s haplotype was type 19 (Benin); -thalassemia-2 was rare. Three -thalassemia alleles (IVS-I-110, GA; codon 39, CT; IVS-I-6, TC) were present in nearly 85% of the -thalassemia alleles; their frequencies were intermediate between those observed in the populations of neighboring countries. A few rare mutations were also found, which might have originated in India, Turkey, Macedonia, and Greece. Nearly all patients with Hb S--thalassemia had the IVS-I-110 (GA) mutation. The frequencies of 11 -thalassemia mutations in 17 mostly Mediterranean countries have been reviewed.     

Genetic studies of water buffalo blood markers. I. Red cell acid phosphatase,albumin, catalase,red cell α-esterase-3, group-specific component,and protease inhibitor

We have developed the methodologies for typing and family studies to establish the modes of inheritance of water buffalo red cell acid phosphatase (Acp), protease inhibitor (Pi), and group-specific component (Gc) on isoelectric focusing and albumin (Alb), red cell -esterase-3 (Est-3), and catalase (Cat) on polyacrylamide gel electrophoresis. Family studies showed that Pi, Gc, Alb, and Cat are coded by autosomal genes with two codominant alleles, while Est-3 is autosomal with two codominant alleles and a recessive null allele and Acp exhibits three codominant alleles.This project was funded by the Australian Centre for International Agricultural Research through Grant PN 8364 and the Malaysian programme for Intensification of Research in Priority Areas through Grant IRPA 1-07-05-057.     

Why does the mammalian red blood cell have aquaporins?

Aquaporins are now known to mediate the rapid exchange of water across the plasma membranes of diverse cell types. This exchange has been studied and kinetically characterized in red blood cells (erythrocytes; RBC) from many animal species. In recent years, a favoured method has been one based on NMR spectroscopy. Despite knowledge of their molecular structure the physiological raison d' etre of aquaporins in RBCs is still only speculated upon. Here, we present two hypotheses that account for the fact that the exchange of water is so fast in RBCs. The first is denoted the "oscillating sieve" hypothesis and it posits that known membrane undulations at frequencies up to 30 Hz with displacements up to 0.3 microm are energetically favoured by the high water permeability of the membrane. The second denoted the "water displacement" hypothesis is based on the known rapid exchange across the RBC membrane of ions such as Cl- and HCO3- and solutes such as glucose, all of whose molecular volumes are significantly greater than that of water. The ideas are generalizable to other cell types and organelles.     

Different pattern of T cell receptor δ gene rearrangement in tumour-infiltrating lymphocytes and peripheral blood in patients with solid tumours

Tumor-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) from four patients with renal-cell carcinoma (three paired with blood), two colon carcinomas (both paired with blood) and two melanomas (blood was not available) were analysed for the T cell receptor (TCR) gene repertoire. Polymerase chain reaction analysis, employing a panel of specific primers for TCR gene segments, showed different gene rearrangement patterns in TIL and PBL in all patients. Simultaneous analysis of TIL and PBL revealed the presence of lymphoid cells in the tumour tissue that were not present in the periphery. These results demonstrate that, although tumor-infiltrating lymphocytes contain / T cells within the range observed in peripheral blood, these cells differ from those in peripheral blood in their gene repertoire and this may account for selective accumulation or/and in situ amplification of / lymphocytes at the tumour site, indicating a unique type of host reaction against tumors.     

Highly conserved,but highly specific: Somatic cell–cell fusion in filamentous fungi

The development of ascomycete fungal colonies involves cell–cell fusion at different growth stages. In the model fungus Neurospora crassa, communication of two fusing cells is mediated by an unusual signaling mechanism, in which the two partners take turns in signal sending and receiving. In recent years, the molecular basis of this unusual cellular behavior has started to unfold, indicating the presence of an excitable signaling network. New evidence suggests that this communication system is highly conserved in ascomycete fungi and, unexpectedly, even mediates interspecies interactions. At the same time, intricate allorecognition mechanisms were identified, which prevent the fusion of genetically unlike individuals. These observations suggest that signal specificity during fungal social behavior has not evolved on the level of signals and receptors, but is achieved at downstream checkpoints. Despite growing insight into the molecular mechanisms controlling self and non-self fungal interactions, their role in natural environments remains largely unknown.     

Effects of density on goldfish blood—II cell morphology

• 1.1. Significant changes in morphology and distribution of red blood cells were observed in blood from adult goldfish held at two loading densities (0.80 and 4.19 fish cm/1 water).
• 2.2. Changes associated with fish held at high density included decreased counts of red blood cells and thrombocytes and an increase in lymphocytes and total leucocytes.
• 3.3. Smaller red blood cells were also found in fish held at high density.

     

Defining “poor mobilizer” in pediatric patients who need an autologous peripheral blood progenitor cell transplantation

The definition of poor mobilizers is not clear in pediatric patients undergoing autologous peripheral blood hematopoietic progenitor cell (HPC) mobilization. Most studies conducted in children define those variables related to the collection of HPC after leukapheresis, but the information regarding exclusively the mobilization process is scarce. In our experience, most children (92.2%) reach the target CD34⁺ cell dose for autologous peripheral blood progenitor cell transplantation if CD34⁺ cell count was higher than 10/μL. No differences were observed between those with >20 CD34⁺ cells/μL and 11–20 CD34⁺ cells/μL. In this study, we analyzed the variables that influence CD34⁺ cell count; we found that prior use of radiotherapy was the main variable related to poor mobilization. Patients diagnosed with Ewing sarcoma, treated with radiotherapy and mobilized with standard doses of granulocyte colony-stimulating factor (G-CSF) were also at a high risk of mobilization failure. In these patients, we should consider mobilization with high dose G-CSF and be prepared with new mobilization agents to avoid delay on their course of chemotherapy.     

Red blood cell fatty acid compositions in a patient with autistic spectrum disorder: a characteristic abnormality in neurodevelopmental disorders?

The fatty acid compositions of red blood cell (RBC) phospholipids from a patient with autistic spectrum disorder (ASD) had reduced percentages of highly unsaturated fatty acids (HUFA) compared to control samples. The percentage of HUFA in the RBC from the autistic patient was dramatically reduced (up to 70%) when the sample was stored for 6 weeks at -20 degrees C. However, only minor HUFA reductions were recorded in control samples stored similarly, or when the autistic sample was stored at -80 degrees C. A similar instability in RBC HUFA compositions upon storage at -20 degrees C has been recorded in schizophrenic patients. In a number of other neurodevelopmental conditions, including attention deficit hyperactivity disorder (ADHD) and dyslexia, reduced concentrations of RBC HUFA have been recorded. The extent and nature of these aberrations require further assessment to determine a possible common biochemical origin of neurodevelopmental disorders in general. To facilitate this, a large scale assessment of RBC fatty acid compositions in patients with ASD, and related disorders, should be performed as a matter of urgency. Supplementing cells in culture with the tryptophan metabolite indole acrylic acid (IAA) affected the levels of cellular HUFA and prostaglandin production. Indole acroyl glycine (IAG), a metabolite of IAA excreted in urine, is found in high concentrations in patients with neurodevelopmental disorders including ASD, ADHD, dyslexia, Asperger's syndrome and obsessive compulsive disorder.     

The role of IFN-γ in regulation of IFN-γ-inducible protein 10 (IP-10) expression in lung epithelial cell and peripheral blood mononuclear cell co-cultures

Background

Epithelial to mesenchymal transition (EMT) in alveolar epithelial cells (AECs) has been widely observed in patients suffering interstitial pulmonary fibrosis. In vitro studies have also demonstrated that AECs could convert into myofibroblasts following exposure to TGF-β1. In this study, we examined whether EMT occurs in bleomycin (BLM) induced pulmonary fibrosis, and the involvement of bronchial epithelial cells (BECs) in the EMT. Using an α-smooth muscle actin-Cre transgenic mouse (α-SMA-Cre/R26R) strain, we labelled myofibroblasts in vivo. We also performed a phenotypic analysis of human BEC lines during TGF-β1 stimulation in vitro.

Methods

We generated the α-SMA-Cre mouse strain by pronuclear microinjection with a Cre recombinase cDNA driven by the mouse α-smooth muscle actin (α-SMA) promoter. α-SMA-Cre mice were crossed with the Cre-dependent LacZ expressing strain R26R to produce the double transgenic strain α-SMA-Cre/R26R. β-galactosidase (βgal) staining, α-SMA and smooth muscle myosin heavy chains immunostaining were carried out simultaneously to confirm the specificity of expression of the transgenic reporter within smooth muscle cells (SMCs) under physiological conditions. BLM-induced peribronchial fibrosis in α-SMA-Cre/R26R mice was examined by pulmonary βgal staining and α-SMA immunofluorescence staining. To confirm in vivo observations of BECs undergoing EMT, we stimulated human BEC line 16HBE with TGF-β1 and examined the localization of the myofibroblast markers α-SMA and F-actin, and the epithelial marker E-cadherin by immunofluorescence.

Results

βgal staining in organs of healthy α-SMA-Cre/R26R mice corresponded with the distribution of SMCs, as confirmed by α-SMA and SM-MHC immunostaining. BLM-treated mice showed significantly enhanced βgal staining in subepithelial areas in bronchi, terminal bronchioles and walls of pulmonary vessels. Some AECs in certain peribronchial areas or even a small subset of BECs were also positively stained, as confirmed by α-SMA immunostaining. In vitro, addition of TGF-β1 to 16HBE cells could also stimulate the expression of α-SMA and F-actin, while E-cadherin was decreased, consistent with an EMT.

Conclusion

We observed airway EMT in BLM-induced peribronchial fibrosis mice. BECs, like AECs, have the capacity to undergo EMT and to contribute to mesenchymal expansion in pulmonary fibrosis.