Red Blood Cell Membrane Proteins Research Articles

Erythrocyte-biomimetic nanosystems to improve antitumor effects of paclitaxel on epithelial cancers.

Chemotherapy is a difficult treatment for cancer patients because of the low effective accumulation of chemo-drugs and their detrimental side effects. Nanoparticles have shown promise as a solution to these problems. However, the known differences in the porosity and vascularization of tumor vessels, and other factors, including the potential formation of a "protein crown," the short half-life time in circulation, and the low drug distribution, often limit their application. To address these problems, biomimetic nanoparticles coated with cell membranes have been developed and shown to have advantages such as prolonged circulation, high biocompatibility, and enhanced targeting abilities in drugs and nanoparticles, thus exhibiting good application prospects in cancer therapy for liver, lung, and melanoma cancers. Accordingly, we designed a PH-sensitive biomimetic nanodrug delivery system with a delicate "core-shell" structure based on red blood cell membranes. Briefly, core nanoparticles were synthesized by the self-assembly of natural amphoteric polymers, including hydrophilic carboxymethylcellulose sodium and hydrophobic stearic acid. For the shell structure, red blood cell membranes were modified using folic acid by a lipid tether (1,2-distearoyl-sn-glycero-3-phosphoethanolamine) to increase tumor-targeting ability, whereas polyethylene glycol was inserted to decrease lipid tether modification-induced potential sequestration by either the mononuclear phagocyte system or the reticuloendothelial system. Via a series of formulation optimizations, paclitaxel was packaged into the red blood membrane-based core-shell nanoparticles with an average size of 226.9±2.75nm and a negative Zeta potential of -14.5±0.3mV. More importantly, the examinations focusing on CD47, a representative red blood cell membrane protein, revealed not only the successful establishment of the membrane shell but also the right-side-out membrane orientation on our core-shell nanoparticles. Our nanodrug delivery system showed good biocompatibility and sensitivity to acidic tumor microenvironments while effectively prolonging the circulation time of paclitaxel and further enhancing its antitumor effects on epithelial malignancies, including liver, lung, and melanoma cancers. In particular, our nanodrug delivery system significantly alleviated paclitaxel-induced renal toxicity. Taken together, our findings highlight that the red blood membrane-based core-shell nanoparticle is a promising biomimetic nanodrug delivery system for functionally delivering chemotherapeutic drugs, and it has promise in clinical applications.

Detection of Red Blood Cell Membrane Proteins in Myelodysplastic Syndromes Using Eosin-5-Maleimide (EMA) Staining by Flow Cytometry.

Background: Eosin-5-Maleimide (EMA)-based flow cytometry binds to red blood cell (RBC) membrane-associated proteins which can be used to detect red blood cell (RBC) membrane disorders. Myelodysplastic syndromes (MDS) are stem cell disorders resulting in ineffective hematopoiesis which is commonly present with anemia and erythroid dysplasia. Objectives: We aimed to study RBC membrane defects in MDS using flow cytometry for EMA staining. Methods: We enrolled anemic patients who were diagnosed with low-risk MDS (R-IPSS score ≤ 3.5), RBC membrane disorders [hereditary spherocytosis (HS) and Southeast Asian ovalocytosis (SAO)], and normal controls. Complete blood count (CBC) and flow cytometry for EMA staining were performed. Results: There were 16 cases of low-risk MDS, 6 cases of RBC membrane disorders, and 15 control cases. Mean fluorescence intensity (MFI) of EMA binding test in the RBC membrane disorders was significantly lower than controls (17.6 vs. 24.3, p < 0.001), but the EMA binding test in the low-risk MDS was not significantly different than the controls (26.5 vs. 24.3, p = 0.08). Conclusion: the RBC membrane defect in low-risk MDS was not demonstrated as having detection ability using EMA binding test with flow cytometry.

Protein composition and functional parameters of RBC membranes in liver and kidney transplantation

Organ transplantation is an effective treatment for many end-stage diseases. However, reperfusion injury constitutes a major complication of transplantation, which is associated with microcirculatory disorders and aggregation of blood corpuscles. Red blood cells (RBC) play an essential role in maintaining hemodynamic and rheological properties of the blood. Moreover, the study of mechanisms of changes in RBC functional indices is an urgent task. The main indicator of RBC functioning is the stability of RBC membrane structure. The issue of RBC membrane modification in organ transplantation has not been studied so far. Objective: to study the protein composition of RBC membranes, their aggregation and electrokinetic parameters in liver and kidney recipients, as well as in related kidney and liver fragment donors before and after operation. Research materials. Blood of 12 kidney recipients and 5 related kidney donors, 8 liver recipients and 4 related liver fragment donors – 1–2 hours before surgery, 1 week, 1, 2, 7, 10, 12 months after surgery. The control group consisted of 8 healthy volunteers. Research methods. Protein separation was done by Laemmli electrophoresis. RBC electrophoretic mobility, which characterizes the electrokinetic properties of cells, was measured by microelectrophoresis. Aggregation was calculated microscopically by counting unaggregated RBCs. Obtained values were compared by Mann-Whitney U test. Results. Examination of the RBC membrane of kidney recipients revealed a significant decrease in the amount of Band 3 protein and glycophorin before and after transplantation. Band 3 protein levels reduced at 1 month, glycophorin reduced at 7 months after surgery, with a maximum decrease in these protein fractions by more than 50% by 7 days compared with control values. There was also a decrease in spectrin content for 2 months after surgery with a maximum decrease of 30% by 1 month. In liver recipients, analysis of RBC membrane proteins revealed a decrease in the amount of glycophorin before surgery and further decrease at 2 months of post-transplant period. The maximum decrease in this index was 72% by 7 days after surgery. In addition, there was a fall in spectrin and Band 3 protein levels at 1 month by more than 60% relative to the control values. In donors, there were changes in the protein fraction of RBC membranes in the long-term post-operative period: spectrin and Band 3 protein levels reduced by 2 times at month 2 in kidney donors, while glycophorin levels reduced by 2.3 times at month 1 after operation in liver donors. Similarly, both groups of donors had increased actin levels at month 1 after surgery. The revealed changes in protein levels in the protein phase of RBC membranes were combined with functional indices of RBCs. In kidney recipients, decreased RBC electrophoretic mobility and increased aggregation were detected at 2 months. In liver recipients, the changes in these indicators were at 1 month. A decrease in RBC electrophoretic mobility was detected in donors of both groups. Conclusion. Changes in RBC membrane electronegativity are associated with changes in glycophorin and Band 3 protein levels, whereas in RBC aggregation process in liver/kidney recipients, the structural and functional disorders in the interrelationships of such membrane proteins as spectrin, Band 3 protein, and glycophorin, are significant factors. Alteration of actin determines inhibition of RBC aggregation growth in donors.

Contemporary uses of old folks: the immunomodulatory and toxic potential of fenbufen

Fenbfen is used for pain, pyrexia and in the management of osteoarthritis, rheumatoid arthritis and other musculoskeletal disorders. The present research was planned to examine the immunomodulatory activity of fenbufen in different models of cell-mediated immunity (CMI) and humoral immunity (HI). The CMI was evaluated by delayed-type hypersensitivity (DTH) and cyclophosphamide-induced neutropenia assays while HI was appraised by hemagglutination (HA) assay by administering fenbufen at 2, 6 and 10 mg.kg-1 and azathioprine 40 mg.kg-1 (as standard therapy) to albino mice by intraperitoneal route. The ex vivo immunomodulatory action was determined by red blood cell (RBC) membrane stabilization and protein denaturation assays. The results showed that fenbufen treatment had significantly (p&lt;0.05-p&lt;0.001) reduced white blood cells, hemoglobin content, and red blood cells in the healthy and neutropenic mice. A significant (p&lt;0.001) reduction in activities of superoxide dismutase and catalase and glutathione contents, and enhancement of malondialdehyde level were observed in neutropenic mice that were restored by fenbufen treatment. It suppressed DTH reaction after 24, 48 and 72 h post topical application of 2, 4-dinitrofluorobenzene (DNFB). Fenbufen or azathioprine treated groups also showed a significant reduction in the antibody titer against human RBCs induced immune activation in mice as compared to the disease control mice. Fenbufen showed IC50 of 14.0, 50.5 and 66.2 μg.ml-1 whereas, diclofenac sodium showed IC50 of 61.0, 126 and 50.5 μg/ml in RBCs membrane stabilization, egg albumin and bovine serum albumin denaturation assays respectively. The current study shows that fenbufen might have potential immunomodulatory activity against CMI and HI. It can be utilized to treat immune system disorders.

SEC23B Loss-of-Function Suppresses Hepcidin Expression by Impairing Glycosylation Pathway in Human Hepatic Cells.

Biallelic pathogenic variants in the SEC23B gene cause congenital dyserythropoietic anemia type II (CDA II), a rare hereditary disorder hallmarked by ineffective erythropoiesis, hemolysis, erythroblast morphological abnormalities, and hypo-glycosylation of some red blood cell membrane proteins. Abnormalities in SEC23B, which encodes the homonymous cytoplasmic COPII (coat protein complex II) component, disturb the endoplasmic reticulum to Golgi trafficking and affect different glycosylation pathways. The most harmful complication of CDA II is the severe iron overload. Within our case series (28 CDA II patients), approximately 36% of them exhibit severe iron overload despite mild degree of anemia and slightly increased levels of ERFE (the only erythroid regulator of hepcidin suppression). Thus, we hypothesized a direct role of SEC23B loss-of-function in the pathomechanism of hepatic iron overload. We established a hepatic cell line, HuH7, stably silenced for SEC23B. In silenced cells, we observed significant alterations of the iron status, due to both the alteration in BMP/SMADs pathway effectors and a reduced capability to sense BMP6 stimulus. We demonstrated that the loss-of-function of SEC23B is responsible of the impairment in glycosylation of the membrane proteins involved in the activation of the BMP/SMADs pathway with subsequent hepcidin suppression. Most of these data were confirmed in another hepatic cell line, HepG2, stably silenced for SEC23B. Our findings suggested that the pathogenic mechanism of iron overload in CDA II is associated to both ineffective erythropoiesis and to a specific involvement of SEC23B pathogenic variants at hepatic level. Finally, we demonstrated the ability of SEC23B paralog, i.e., SEC23A, to rescue the hepcidin suppression, highlighting the functional overlap between the two SEC23 paralogs in human hepatic cells.

Neutrophil Cathepsin G Enhances Thrombogenicity of Mildly Injured Arteries via ADP-Mediated Platelet Sensitization.

Inhalation of particulate matter in polluted air causes direct, size-restricted passage in the circulation and pronounced lung inflammation, provoking platelet activation and (non)-fatal cardiovascular complications. To determine potency and mechanism of platelet sensitization via neutrophil enzymes, we performed in vitro aggregation studies in washed human platelets and in murine and human blood, in the presence of elastase, cathepsin G and regular platelet agonists, present in damaged arteries. The impact of both enzymes on in vivo thrombogenicity was studied in the same thrombosis mouse model, previously having demonstrated that neutrophil activation enhances peripheral thrombogenicity. At 0.05 U/mL, cathepsin G activated washed human platelets via PAR1, whereas at 0.35 U/mL, aggregation occurred via PAR4. In Swiss mouse platelet-rich plasma no aggregation occurred by cathepsin G at 0.4 U/mL. In human and murine blood, aggregations by 0.05–0.1 U/mL cathepsin G were similar and not PAR-mediated, but platelet aggregation was inhibited by ADP antagonists, advocating cathepsin G-released ADP in blood as the true agonist of sustained platelet activation. In the mouse thrombosis model, cathepsin G and elastase amplified mild thrombogenicity at blood concentrations that activated platelets in vitro. This study shows that cathepsin G and elastase secreted in the circulation during mild air pollution-induced lung inflammation lyse red blood cell membrane proteins, leading to ADP-leakage into plasma, sensitizing platelets and amplifying their contribution to cardiovascular complications of ambient particle inhalation.

Erythrocyte membrane-camouflaged gefitinib/albumin nanoparticles for tumor imaging and targeted therapy against lung cancer

Conventional chemotherapeutic drugs may cause serious side effects such as hepatotoxicity and renal toxicity due to lack of targeting, which affects therapy outcome and the prognosis of patients. Therefore, biomimetic nanoparticles with long blood circulation and active targeting have attracted increasing attention. In this work, we fabricated a biomimetic R-RBC@GEF-NPs nano-system by encapsulating gefitinib-loaded albumin nanoparticles (GEF-NPs) inside cRGD-modified red blood cell (RBC) membranes. The complete RBC membrane structure and membrane proteins enabled the NPs to escape phagocytosis by macrophages. In addition, the cRGD moiety significantly improved tumor cell targeting and uptake. R-RBC@GEF-NPs inhibited the growth of A549 cells in vitro in a dose- and time-dependent manner by inducing apoptosis and cell cycle arrest at the G1 phase. Likewise, the R-RBC@GEF-NPs also decreased tumor weight and volume in the mice injected with A549 cells and prolonged survival time. In addition, the 99Tc-labeled R-RBC@GEF-NPs selectively accumulated in the tumor tissues in vivo, and enabled real time tumor imaging. Finally, blood and histological analyses showed that R-RBC@GEF-NPs did not cause any obvious systemic toxicity. Taken together, the biomimetic R-RBC@GEF-NPs is a promising therapeutic formulation for the treatment of lung cancer.

Xylia xylocarpa (Roxb.) Taub. Leaves Ameliorates Inflammation and Pain in Experimental Mice and Computer-Aided Model

Xylia xylocarpa (Roxb.) Taub. is traditionally used to treat several diseases, including leprosy, wound healing, gonorrhea, rheumatism, anemia, diarrhea and ulcer. This study evaluated the anti-inflammatory and anti-nociceptive activities of methanolic extract of Xylia xylocarpa leaves (MEXX) via in vitro, in vivo as well as in silico models. In vitro anti-inflammatory activity was determined by human red blood cell membrane stabilization study and protein denaturation while in vivo anti-nociceptive activity was examined by the acetic acid-induced writhing test (AAWT) and formalin-induced paw licking test (FIPLT). Additionally, trans-5-hydroxypipecolic acid was an identified compound of MEXX which was subjected to molecular docking analysis followed by ADME/T and toxicity analysis. Qualitative phytochemical screening revealed that MEXX was enriched with carbohydrates, flavonoids, alkaloids, proteins, tannins and showed significant total phenolic (1222.66 ± 0.66 mg GAE/g dried extract) and flavonoids contents (325.33 ± 1.76 mg QE/g dried extract) in quantitative phytochemical screening. Inflammatory studies unveiled that; MEXX significantly (p &lt; 0.05) inhibited the hemolysis of membrane and protein at different concentrations (31.25 - 1000 μg/mL). The extract also displayed statistically significant analgesic responses in the acetic acid and formalin-induced test at several doses (200 and 400 mg/kg b.w). In AAWT, the extract exhibited 13.67 and 51.37 % inhibition of writhing at the doses 200 and 400 mg/kg body weight respectively. In formalin-induced paw licking test, the early phase pain inhibition was 54.64 % at the concentration of 400 mg/kg while during the latter phase at 400 mg/kg, the inhibition of pain was 43.82 %. According to molecular docking analysis, trans-5-hydroxypipecolic acid demonstrated a promising docking score against PDE4, COX-1, and COX-2 along with satisfied pharmacokinetic and toxicological properties. Finally, from the results it could be concluded that MEXX has potential anti-inflammatory and an-nociceptive effects that should require further investigation.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Xylia xylocarpa minimizes the inflamation and pain&#x0D; Xylia xylocarpa showed significant analgesic activity&#x0D; Xylia xylocarpa revealed polyphenolic compounds including phenol, and flavonoid&#x0D; In in silico, trans-5-hydroxypipecolic acid possessed significant analgesic activity against COX-1 and COX-2&#x0D; &#x0D; GRAPHICAL ABSTRACT

N-Glycomics of Human Erythrocytes.

Glycosylation is a complex post-translational modification that conveys functional diversity to glycoconjugates. Cell surface glycosylation mediates several biological activities such as induction of the intracellular signaling pathway and pathogen recognition. Red blood cell (RBC) membrane N-glycans determine blood type and influence cell lifespan. Although several proteomic studies have been carried out, the glycosylation of RBC membrane proteins has not been systematically investigated. This work aims at exploring the human RBC N-glycome by high-sensitivity MALDI-MS techniques to outline a fingerprint of RBC N-glycans. To this purpose, the MALDI-TOF spectra of healthy subjects harboring different blood groups were acquired. Results showed the predominant occurrence of neutral and sialylated complex N-glycans with bisected N-acetylglucosamine and core- and/or antennary fucosylation. In the higher mass region, these species presented with multiple N-acetyllactosamine repeating units. Amongst the detected glycoforms, the presence of glycans bearing ABO(H) antigens allowed us to define a distinctive spectrum for each blood group. For the first time, advanced glycomic techniques have been applied to a comprehensive exploration of human RBC N-glycosylation, providing a new tool for the early detection of distinct glycome changes associated with disease conditions as well as for understanding the molecular recognition of pathogens.

A Study of Novel Beta Globin Mutation Associated with Dominant Beta-Thalassemia, Aberrant Erythroid Maturation and Differentiation Compounded with Hereditary Pyropoikilocytosis

Background: Heterozygosity for a beta-thalassemia mutation is clinically insignificant; however, microcytosis and mild anemia are oftenpresent. Rare mutations in the proximal half of the coding sequence for the beta globin gene (HBB) have been shown to cause an apparent autosomal dominant beta thalassemia that is associated with more severe anemia. These mutations often produce a frame shift in HBB mRNA; however, detection of the mutant transcript and/or protein has been controversial. In genotypically identical relatives, a milder phenotype can sometimes be observed, while others have severe anemia. It has been suggested that these phenotypic differences may be mediated by variations in destruction of mutant HBB transcripts by nonsense mediated decay .Materials: We studied a Dominican man with severe microcytic hypochromic anemia without iron deficiency, suggestive of thalassemia, and his family. We performed a detailed erythrocyte evaluation, including morphologic and hemoglobinopathy evaluations, globin sequencing, hemoglobin (Hb) stability evaluation, and band-3 testing for red blood cell (RBC) membrane abnormality, and analyzed DNA for mutations of genes encoding for RBC membrane proteins. We also performed in vitro expansion of erythroid progenitors, examined erythroid differentiation and proliferation, and searched for mutant HBB transcripts.Results: The propositus was found to have a novel beta-thalassemia mutation, HBB282delT encoding a Cys93fs (frame shift). He also had Heinz bodies and was positive for an unstable Hb (by isopropanol test), but had no electrophoretically detectable mutant Hb, and had absolute reticulocytopenia (Table). Peripheral blood had a typical hereditary pyropoikilocytosis (HPP) morphology (Figure 1), confirmed by band-3 testing. Family studies (Table) showed that the situation was more complex. His asymptomatic wife and one son had sickle cell trait (Table), and two other children inherited both the HBB282delT mutation and a Hb S mutation and were positive for band-3 deficiency testing. Their RBCs had typical HPP morphology, along with sickle cells (Figure 2), and had high HbF levels (Table). Reticulocytes were not available for detection of mutant transcripts by RNA analysis; we therefore performed in vitro expansion of erythroid progenitors in a 3-week liquid erythroid culture model (Gaikwad, et al, Exp Hemat, 2007). We detected mutant HBB282delT transcripts leading to a frameshift in exon 2, codon 93, where 9 new codons downstream from the mutation were encoded. The mutant transcript was present in equal amounts with the HBB transcript from the wild allele. Analysis of erythroid proliferation and differentiation revealed a marked decrease in proliferation (as determined by number of glycophorin-positive cells) and decreased differentiation (as evaluated by temporal changes of glycophorin and transferrin receptor positivity and intensity) in the propositus and two children with HBB 282delT. Hemoglobinization of their maturing erythroid progenitors was not discernible in 14-day cultures, in contrast to his wife, the asymptomatic son and the controls who had readily discernible hemoglobinized (red) progenitors. By day 21 of culture, he and the 2 affected children had only faintly hemoglobinized cells that appeared pink rather than red, and the erythroid progenitors of the propositus had minimal differentiation. None of the affected individuals had a SPTA1 exon 2 mutation, the most common missense mutations leading to the HPP phenotype.Discussion: We describe a novel HBB mutation associated with severe anemia, reticulocytopenia, and impaired erythropoiesis with delayed erythroid maturation and impaired hemoglobinization. The presented data suggest that the mutant protein is unstable and presumably toxic to erythroid progenitors. The mutant protein is not identifiable by routine hemoglobin studies and its presence will be evaluated by studies of precipitated hemoglobin (Heinz bodies and hemoglobin precipitates after isopropanol exposure). Effects of the mutant protein on maturation and differentiation can be assessed by RNAseq of erythroid progenitors compared to normal controls of the same stage of erythroid differentiation. The molecular basis of HPP is being evaluated by DNA sequencing of targeted genes encoding RBC membrane proteins and comparing their potential functional relevance to the HPP phenotype. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Insight into Francisella tularensis-erythrocyte interactions

Francisella tularensis, the causative agent of tularemia, is a pathogenic gram-negative bacterium that enters human red blood cells (RBCs). Previous investigations suggest that invasion of RBCs helps F. tularensis survive in the gut of arthropods – a transmission vector of this bacterium leading to colonization. Since tularemia is a zoonotic infection, humans are not the primary host of F. tularensis. Therefore, we sought to investigate whether F. tularensis was capable of invading RBCs of other animals. Using the gentamicin protection assay, we discovered that while F. tularensis could enter sheep and chicken erythrocytes, bovine RBCs did not support invasion. Because of previous studies published by our lab, and due to intrinsic differences between human and bovine erythrocyte surface protein Band 3, we hypothesized that RBC membrane protein Band 3 is required for invasion. We used anti-band 3 Fab fragments to physically block the Band 3 RBC surface protein and investigated how that impacted F. tularensis invasion. Here, we provide preliminary evidence suggesting that F. tularensis uses Band 3 to enter human RBCs. This study was funded by the National Institute of Allergy and Infectious Diseases (1R15HL147135) and an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health (P20GM103434), which funds WV-INBRE program.

Ektacytometry Analysis of Post-splenectomy Red Blood Cell Properties Identifies Cell Membrane Stability Test as a Novel Biomarker of Membrane Health in Hereditary Spherocytosis.

Hereditary spherocytosis (HS) is the most common form of hereditary chronic hemolytic anemia. It is caused by mutations in red blood cell (RBC) membrane and cytoskeletal proteins, which compromise membrane integrity, leading to vesiculation. Eventually, this leads to entrapment of poorly deformable spherocytes in the spleen. Splenectomy is a procedure often performed in HS. The clinical benefit results from removing the primary site of destruction, thereby improving RBC survival. But whether changes in RBC properties contribute to the clinical benefit of splenectomy is unknown. In this study we used ektacytometry to investigate the longitudinal effects of splenectomy on RBC properties in five well-characterized HS patients at four different time points and in a case-control cohort of 26 HS patients. Osmotic gradient ektacytometry showed that splenectomy resulted in improved intracellular viscosity (hydration state) whereas total surface area and surface-to-volume ratio remained essentially unchanged. The cell membrane stability test (CMST), which assesses the in vitro response to shear stress, showed that after splenectomy, HS RBCs had partly regained the ability to shed membrane, a property of healthy RBCs, which was confirmed in the case-control cohort. In particular the CMST holds promise as a novel biomarker in HS that reflects RBC membrane health and may be used to asses treatment response in HS.

Novel mechanism of hereditary pyropoikilocytosis phenotype due to co‐inheritance of β globin and α spectrin mutations

Novel mechanism of hereditary pyropoikilocytosis phenotype due to co‐inheritance of β globin and α spectrin mutations

Anti-inflammatory activity of Nectandra angustifolia (Laurel Amarillo) ethanolic extract

Ethnopharmacological relevanceNectandra angustifolia belongs to the Lauraceae family and it is widely known in phytomedicine by local inhabitants of South America against various maladies. It is popularly used for the treatment of different types of inflammatory processes, like rheumatism, arthritis and its associated pain. Aim of the studyTo characterize the phytochemicals in an ethanolic extract of Nectandra angustifolia and to evaluate the total antioxidant content and its anti-inflammatory effect with multiparametric analyses through in vitro assays and an in vivo model. MethodsLeaves and stems of Nectandra angustifolia were air-dried and an ethanolic extract (NaE) was further obtained. Total phenolic, flavonoid and tannin content were determined and the antioxidant activity was addressed by DPPH and FRAP assays. NaE was first analyzed by HPLC and then two tests were carried out as screening assays for anti-inflammatory activities: red blood cell membrane stabilization and protein denaturation. The non-cytotoxic concentration of NaE was determined for in vitro biological assays using RAW 264.7 (murine macrophages) cell cultures through cell counting with Trypan-blue and XTT assay. Subsequently, the cell cycle of RAW 264.7 cells exposed for 24 h to NaE was analyzed. Additionally, the anti-inflammatory capacity of NaE was evaluated by RT-qPCR of pro-inflammatory cytokines. Furthermore, NF-κB translocation was observed by confocal microscopy at different times. Finally, formalin-induced mice paw inflammation was used as an in vivo model. ResultsThe chromatographic profile of NaE showed peaks compatible with flavonoids content. NaE exhibited better membrane stabilization effect on HRBC and protection of BSA denaturation than the standard drug (diclofenac). NaE diminished mRNA levels of pro-inflammatory cytokines when added 1-h prior LPS stimulation. Moreover, NaE prevented the translocation of NF-κB to the nucleus and in formalin-induced mice paw inflammation, reduced the edema and the stimulus of inflammatory phase. ConclusionThis study shows for the first time, that Nectandra angustifolia ethanolic extract has a high content of flavonoids and that possess antioxidant and anti-inflammatory biological properties as demonstrated by multiparametric analyses from in vitro assays and an in vivo model of inflammation.

Calcium/protein kinase C signaling mechanisms in shear-induced mechanical responses of red blood cells

Red blood cell (RBC) deformability has vital importance for microcirculation in the body, as RBCs travel in narrow capillaries under shear stress. Deformability can be defined as a remarkable cell ability to change shape in response to an external force which allows the cell to pass through the narrowest blood capillaries. Previous studies showed that RBC deformability could be regulated by Ca2+/protein kinase C (PKC) signaling mechanisms due to the phosphorylative changes in RBC membrane proteins by kinases and phosphatases. We investigated the roles of Ca2+/PKC signaling pathway on RBC mechanical responses and impaired RBC deformability under continuous shear stress (SS). A protein kinase C inhibitor Chelerythrine, a tyrosine phosphatase inhibitor Calpeptin, and a calcium channel blocker Verapamil were applied into human blood samples in 1 micromolar concentration. Samples with drugs were treated with or without 3 mM Ca2+. A shear stress at 5 Pa level was applied to each sample continuously for 300 s. RBC deformability was measured by a laser-assisted optical rotational cell analyzer (LORRCA) and was calculated as the change in elongation index (EI) of RBC upon a range of shear stress (SS, 0.3–50 Pa). RBC mechanical stress responses were evaluated before and after continuous SS through the parameterization of EI-SS curves. The drug administrations did not produce any significant alterations in RBC mechanical responses when they were applied alone. However, the application of the drugs together with Ca2+ substantially increased RBC deformability compared to calcium alone. Verapamil significantly improved Ca2+-induced impairments of deformability both before and after 5 Pa SS exposure (p < 0.0001). Calpeptin and Chelerythrine significantly ameliorated impaired deformability only after continuous SS (p < 0.05). Shear-induced improvements of deformability were conserved by the drug administrations although shear-induced deformability was impaired when the drugs were applied with calcium. The blocking of Ca2+ channel by Verapamil improved impaired RBC mechanical responses independent of the SS effect. The inhibition of tyrosine phosphatase and protein kinase C by Calpeptin and Chelerythrine, respectively, exhibited ameliorating effects on calcium-impaired deformability with the contribution of shear stress. The modulation of Ca2+/PKC signaling pathway could regulate the mechanical stress responses of RBCs when cells are under continuous SS exposure. Shear-induced improvements in the mechanical properties of RBCs by this signaling mechanism could facilitate RBC flow in the microcirculation of pathophysiological disorders, wherein Ca2+ homeostasis is disturbed and RBC deformability is reduced.

Leaves of Cleome amblyocarpa Barr. And Murb. And Cleome arabica L.: Assessment of nutritional composition and chemical profile (LC-ESI-MS/MS), anti-inflammatory and analgesic effects of their extracts

Ethnopharmacological relevanceThe Cleomaceae family is known for its richness in secondary metabolites and different Cleome species are used in folk medicine. Cleome amblyocarpa and Cleome arabica are medicinal herbs used in Tunisia and other North Africa countries to treat various diseases such as diabetes, rheumatism, colic, pain and digestive disorders. Aim of the studyTo our knowledge, few data are available about the nutritional value, phytochemical components and biological effects of C. arabica and C. amblyocarpa cultivated in Tunisia. For this reason, the present survey aimed to determine the nutritional value, bioactive compounds and pharmacological properties of the leaves of these two species of Cleome. Materials and methodsTo characterize and determine the bioactive compounds in both extracts of leaves of Cleome species, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used. The various nutritional parameters were analyzed, in particular the amounts of protein, carbohydrates, ash, fiber, and total lipids. Vitamin E and fatty acid profiles were also evaluated by HPLC-DAD-FLD and GC-FID, respectively. The acute toxic effects of leaf extracts in mice at concentrations of 100, 500 and 800 mg/kg body weight have been investigated. The anti-inflammatory effect of leaves extracts was examined by means of the in vitro and in vivo models. The in vivo anti-inflammatory test was assessed by means of the carrageenan induced paw edema in rats. For the in vitro anti-inflammatory assay, the red blood cells membrane stabilization and protein denaturation methods were employed. The analgesic effect of hydroalcoholic extracts of leaves was also assessed by acetic acid induced writhing model in mice. ResultsThe phytochemical composition and the nutritional values of the leaves of C. amblyocarpa and C. arabica were determined. Our results revealed that the leaves of C. amblyocarpa are rich in flavonoids and glucosinolates. On the other hand, these latter metabolites are not present in the C. arabica extract and the leaves are characterized by the presence of flavones, methoxyflavones and their glycosides. Our findings revealed that the leaves of the two species contain a potential quantity of vitamins; proteins, carbohydrates and dietary fiber, and their hydroalcoholic extracts indicated substantial anti-inflammatory and antinociceptive activities in all the tests. Additionally, the data from the acute toxicity test proved that the leaf extracts did not cause any mortality or signs of toxicity in animals at doses up to 800 mg/kg ConclusionsThe results obtained in this investigation demonstrated that the leaves of C. arabica and C. amblyocarpa are a valuable source of nutrients and active substances. Our observations support the traditional utilize of these two Cleome species for the treatment of painful diseases and as a source of natural anti-inflammatory agents.

Efficiency of AUTODOCK: Insilico study of Pharmaceutical Drug Molecules

Furthermore, the relative orientation of the two interacting partners may affect the type of signal produced (e.g., agonism vs antagonism). [...]docking is useful for predicting both the strength and type of signal produced. Molecular docking is one of the most frequently used methods in structure-based drug design, due to its ability to predict the binding-conformation of small molecule ligands to the appropriate target binding site. The AutoDock 4.2 programme revealed that hydroxyl group of lupeol formed two hydrogen bonds with the ASP32 (catalytic aspartic residue) and SER35 residues of BACE1 with the binding energy of (-8.2kcal/mol), while the ketone group of lupenone did not form any hydrogen bonds with BACE1 giving evidence for less binding affinity. Lakshmana Rao ATMAKUR and et al used AutoDock softwear for In vitro anti-inflammatory activity was checked by human red blood cell (HRBC) membrane stabilization and protein denaturation.

Characterization of the Underlying Molecular Defect in Hereditary Spherocytosis Associated With Spectrin Deficiency

AbstractSeveral subsets of patients with hereditary spherocytosis (HS) have been defined based on the specific red blood cell membrane protein deficiencies involving spectrin, ankyrin, band 3, and protein 4.2. Mutations of the genes encoding these proteins are currently being uncovered. Regarding spectrin, only three isolated cases of β-spectrin gene mutations were recently reported in association with HS and spectrin deficiency. We have screened the coding region of the β-spectrin gene using the SSCP technique, in 40 families with HS associated with spectrin deficiency or combined spectrin and ankyrin deficiencies. In this report we describe six frameshift and nonsense mutations and four missense mutations of the β-spectrin gene in 11 unrelated families. Taking advantage of modifications in the restriction enzyme recognition sequences introduced by the mutations, we show, in all cases of frameshift and nonsense mutations, the loss of heterozygosity at the cDNA level when compared to genomic DNA, reflecting the absence of the mutant mRNA transcripts. In one family with a large pedigree including six generations and 112 members, we firmly establish the autosomal dominant inheritance of one of the β-spectrin null mutations. Most of the mutations described are responsible for a phenotype of mild to moderate autosomal dominant form of HS associated with a conspicuous spherocytosis with frequent spiculated cells (8% to 15% acanthocytes). One missense mutation appears to be associated with a recessive form of the disease. Five common restriction enzyme polymorphisms of the coding region of the β-spectrin gene are also described. Overall, these findings underscore the importance of the β-spectrin gene mutations in the pathogenesis of HS and reemphasizes the extreme heterogeneity of the underlying molecular basis of this condition.

Alterations in the Properties of Red Blood Cells in Men with Coronary Artery Diseases after Comprehensive Cardiac Rehabilitation.

Purpose Comprehensive cardiac rehabilitation (CCR) is a complex program aimed at improving the health status of patients with coronary artery disease (CAD), especially those who have been subjected to cardiac interventions (PCI and CABG).The aim of this study was to measure the changes in the properties of red blood cells (RBCs) in men with CAD after cardiac intervention and after participation in CCR program. Methods In this study, we have investigated the influence of the physical training-based CCR program in 12 men with CAD, after PCI or CABG. The characteristics of RBCs including the basic morphology of RBCs, the conformational state of RBC membrane protein and hemoglobin, acetylcholinesterase activity, membrane fluidity, the osmotic fragility, and thiol concentration in membrane and in hemolysate were measured. Ascorbate concentration and reduced glutathione were also determined. The analysis was performed in men, before and after participation in CCR. The properties of RBCs were observed in connection with the exercise test, and parameters were evaluated before, immediately after, and 1 hour after the exercise test. Results After CCR, a decrease in the mobility of erythrocyte membrane proteins was observed, which was accompanied by a decrease in lipid fluidity. In addition, immediately after the exercise test and 1 hour later, we measured a decrease in thiol level in hemolysate, but not in the plasma membrane. Unexpectedly, an increase in reduced glutathione concentration one hour after the exercise test after completing comprehensive cardiac rehabilitation was observed. Conclusion CCR in men with CAD after cardiac intervention is connected with decreased membrane fluidity and decreased membrane protein mobility, which indicates that reduction of oxidative changes in these components occurs.

Dehydrated Hereditary Stomatocytosis in a Multi-Generational American Family with a KCNN4 Gardos Channel Mutation

INTRODUCTION: Dehydrated hereditary stomatocytosis (DHSt) is an autosomal dominant red blood cell membrane disorder characterized by hemolytic anemia and splenomegaly. DHSt has an estimated incidence of 1:50,000 births, and the degree of anemia varies within and between families. Although transfusion support during childhood is not uncommon, continued requirement into adulthood is rare. The most frequent cause of DHSt is a gain-of-function mutation of the PIEZO1 gene, leading to delayed channel inactivation that results in a monovalent cation leak and an increase in intracellular calcium (Ca2+). Many of these patients develop recurrent thromboses post splenectomy. Other DHSt patients have mutations in KCNN4, which encodes the Gardos channel, with mutations causing increased Ca2+ sensitivity and potassium efflux. To our knowledge, 42 patients from ten families have been described with four distinct KCNN4 mutations: Arg352His, Val282Met or Val282Glu, and a 28bp deletion encompassing the exon-intron 7 junction. We report herein the eighth family with the Arg352His locus mutation. CASE REPORT: Five subjects from a single family were enrolled in this study (affected proband, unaffected husband, two affected children, and an unaffected grandchild). The proband has had hemolytic anemia since childhood. She had undergone splenectomy at age three and cholecystectomy at eight. Her anemia persisted, with a mean hemoglobin (Hgb) of 10.5g/dL and a reticulocyte count (retic ct) of 12.6%, with no need for transfusion support or iron chelation therapy (Table 1). Extensive testing revealed slightly decreased osmotic fragility and mildly elevated intracellular sodium concentration, of 19.4 mEq/L. Her daughter has mild splenomegaly and anemia, with a mean Hgb of 11.1g/dL and retic ct of 6.7%, whereas her son has more severe disease, with a mean Hgb of 9.3g/dL and a retic ct of &amp;gt;22%. He underwent splenectomy as a teenager for immune thrombocytopenia, and has required chelation therapy with deferasirox since age 31, when his ferritin rose to &amp;gt;1000ng/mL. Similar to results reported by others, splenectomy did not alter the severity of hemolysis in either the proband or her son, and neither developed thrombotic complications 57 and 7 years post splenectomy, respectively. The proband's daughter has a child with a normal Hgb, and is presumed unaffected. Stomatocytes were rarely seen on the peripheral blood smears of the proband and her children. METHODS: A clinically available 39 gene hemolytic anemia panel on the proband failed to identify the mutation underlying this disorder. We therefore performed whole exome sequencing on all five family members. We prioritized the analysis of 23 additional genes that are included in hemolytic anemia panels from two other reference laboratories and are involved in disorders of red blood cell membrane or cytoskeletal proteins of potential clinical relevance to the study population. RESULTS: A single missense mutation, Arg352His within KCNN4, was identified in all three affected individuals. This heterozygous mutation was present in the proband and her affected two children, and absent in her unaffected grandchild and husband. CONCLUSIONS: To our knowledge, this Pennsylvania family is only the eleventh described to have DHSt secondary to a KCNN4 mutation. This disorder is likely much more prevalent than reported, due to the rarity of stomatocytes on peripheral blood smears, the omission of the KCNN4 gene from hemolytic panels offered by some reference laboratories, and variable clinical presentation. KCNN4 mutations should be investigated if other causes are not identified in patients with lifelong hemolytic anemia suspected of having a red cell membrane protein or cytoskeletal disorder. Appropriate diagnosis may allow severely affected patients to be considered for treatment with the experimental Gardos channel inhibitor senicapoc. Additionally, mutational diagnosis is especially important when considering the adverse outcomes post splenectomy in PIEZO1 as compared to KCNN4 mutations. Disclosures Eyster: SPARK:Research Funding;Sanofi:Research Funding;Novo Nordisk:Research Funding;Baxalta/Shire:Research Funding.