Human erythroid cells are affected by aluminium. Alteration of membrane band 3 protein

Hematologic evaluation of peripheral blood in Sprague Dawley rats by chronic exposure to aluminum chloride (AlCl3)

This study aimed to evaluate whether aluminum chloride (AlCl3) causes hematological changes in the peripheral blood of Sprague-Dawley (SD) rats. Five groups of female SD rats were intragastrically administered with 4 different concentrations of AlCl3 for 5 days a week for a total of 90 days. The aluminum concentration was determined via graphite furnace atomic absorption spectroscopy. Analysis of serum iron-kinetic profiles, blood cytometry outcomes, and blood smears of the blood samples. Scanning electron microscopy (SEM) and Raman spectroscopy were used to search for structural and ultrastructural changes, respectively. Blood aluminum concentration ranged 12.38-16.24 μg/L with no significant difference between experimental treatments. At the AlCl3 concentration of 40 mg Al/kg bw of rats/day, the mean ferritin value in the serum iron kinetic profile was 29.81±6.1 ng/mL, and this value showed a significant difference between experimental treatments. Blood cytometry revealed that there were 6.45-7.11×106 cells/μL erythrocytes, 8.91-9.32×103 cells/μL leukocytes, and 477.2-736.3×103 cells/μL platelets along with a hemoglobin of 37.38-41.93 g/dL and hematocrit level of 37.38-41.93%; the experimental treatments showed no significant differences. Erythrocyte structural analysis using SEM showed no differences between experimental treatments, whereas ultrastructural evaluation using Raman spectroscopy made it possible to identify the following bands: 741, 1123, 1350, 1578, and 1618 cm-1, which were respectively associated with the following vibrational modes and compounds: vibration of the tryptophan ring, asymmetric C-O-C stretching of glucose, C-H curve of tryptophan, C=C stretching of the heme group, and C-N stretching of the heme group, with no significant differences between experimental treatments. Therefore, AlCl3 administration does not induce ultrastructural changes in the erythrocyte membrane. This study revealed that serum ferritin concentration was the only parameter affected by AlCl3 exposure at 40 mg of Al/kg bw of rats/day.

Aluminum Poisoning with Emphasis on Its Mechanism and Treatment of Intoxication

Aluminum poisoning has been reported in some parts of the world. It is one of the global health problems that affect many organs. Aluminum is widely used daily by humans and industries. Residues of aluminum compounds can be found in drinking water, food, air, medicine, deodorants, cosmetics, packaging, many appliances and equipment, buildings, transportation industries, and aerospace engineering. Exposure to high levels of aluminum compounds leads to aluminum poisoning. Aluminum poisoning has complex and multidimensional effects, such as disruption or inhibition of enzymes activities, changing protein synthesis, nucleic acid function, and cell membrane permeability, preventing DNA repair, altering the stability of DNA organization, inhibition of the protein phosphatase 2A (PP2A) activity, increasing reactive oxygen species (ROS) production, inducing oxidative stress, decreasing activity of antioxidant enzymes, altering cellular iron homeostasis, and changing NF-kB, p53, and JNK pathway leading to apoptosis. Aluminum poisoning can affect blood content, musculoskeletal system, kidney, liver, and respiratory and nervous system, and the extent of poisoning can be diagnosed by assaying aluminum compounds in blood, urine, hair, nails, and sweat. Chelator agents such as deferoxamine (DFO) are used in the case of aluminum poisoning. Besides, combination therapies are recommended.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

Effect of aluminum (Al) speciation on erythrocytic antioxidant defense process: Correlations between lipid membrane peroxidation and morphological characteristics

Al contamination becomes a growing problem in human society. Accumulation of Al in blood could destroy the structure and disorder function of erythrocyte, and finally cause blood diseases. In the present study, AlCl₃ and Al(malt)₃ are respectively used in the erythrocyte system, in order to investigate the comparative toxic effect on erythrocyte fragility, the influence on cellular biochemical components and lipid peroxidation level. We find that the osmotic fragility, the number of Heinz bodies, the content of MDA and advanced oxidation protein product of the AlCl₃ treated erythrocytes were higher than the Al(malt)₃ treated erythrocytes at the same concentrations of Al(Ⅲ). The morphological and membrane protein changes of the AlCl₃ treated group show superior to the Al(malt)₃ treated group. In summary, we conclude that the comparative effect on the erythrocyte between organic aluminum and inorganic aluminum is significantly different, and the prime comparative difference between the toxic effects of both the compounds is oxidative stress. Further research should focus on in vivo experiments to confirm the differential toxicity and to elucidate the molecular mechanisms underlying Al-induced erythrocyte toxicity in order to prevent hematological disorders.

Role of Spirulina in mitigating hemato-toxicity in Swiss albino mice exposed to aluminum and aluminum fluoride

Aluminum is ingested through foods, water, air, and even drugs. Its intake is potentiated further through foods and tea prepared in aluminum utensils and Al salt added in the drinking water for removal of suspended impurities and also fluoride in the affected areas. The ameliorating role of a blue green alga Spirulina is well documented to various pollutants in the animal models. We, therefore, examined its protective role (230 mg/kg body weight) on the hematology of male Swiss albino mice treated with aluminum (sub-acute = 78.4 mg/kg body weight for 7 days, sub-chronic = 7.8 mg/kg body weight for 90 days) and aluminum fluoride (sub-acute = 103 mg/kg body weight, sub-chronic = 21 mg/kg body weight), along with their recovery after 90 days of sub-chronic exposure. This study revealed significant reduction in the values of RBC (5-18 %), Hb (15-17 %), PCV (8-14 %), and platelets (26-36 %), and increase in WBC (54-124 %) in the treated mice, particularly after sub-acute exposure. Aluminum fluoride was comparatively more toxic than aluminum. Further, Spirulina supplement not only alleviated toxicity of test chemicals in Swiss albino mice but also led to their better recovery after withdrawal.

Aluminum Trichloride Induces Hypertension and Disturbs the Function of Erythrocyte Membrane in Male Rats

Aluminum (Al) is the most abundant metal in the earth's crust. Al accumulates in erythrocyte and causes toxicity on erythrocyte membrane. The dysfunction of erythrocyte membrane is a potential risk to hypertension. The high Al content in plasma was associated with hypertension. To investigate the effect of AlCl3 on blood pressure and the function of erythrocyte membrane, the rats were intragastrically exposed to 0, 64(1/20 LD50), 128(1/10 LD50), and 256(1/5 LD50) mg/kg body weight AlCl3 in double distilled water for 120 days, respectively. Then, we determined the systolic and mean arterial blood pressures of rats, the osmotic fragility, the percentage of membrane proteins, the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-pX), and malondialdehyde (MDA) content of the erythrocyte membrane in this experiment. The results showed that AlCl3 elevated the systolic and mean arterial blood pressure of rats, increased the osmotic fragility, decreased the percentage of membrane protein, inhibited the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, CAT, SOD and GSH-pX, and increased the MDA content of erythrocyte membrane. These results indicate that AlCl3 may induce hypertension by disturbing the function of erythrocyte membrane.

Protection against oxidative damage in human erythrocytes and preliminary photosafety assessment of Punica granatum seed oil nanoemulsions entrapping polyphenol-rich ethyl acetate fraction

The main purpose of the present study is to evaluate the ability of nanoemulsion entrapping pomegranate peel polyphenol-rich ethyl acetate fraction (EAF) prepared from pomegranate seed oil and medium chain triglyceride to protect human erythrocyte membrane from oxidative damage and to assess preliminary in vitro photosafety. In order to evaluate the phototoxic effect of nanoemulsions, human red blood cells (RBCs) are used as a biological model and the rate of haemolysis and photohaemolysis (5 J cm(-2) UVA) is assessed in vitro. The level of protection against oxidative damage caused by the peroxyl radical generator AAPH in human RBCs as well as its effects on bilayer membrane characteristics such as fluidity, protein profile and RBCs morphology are determined. EAF-loaded nanoemulsions do not promote haemolysis or photohaemolysis. Anisotropy measurements show that nanoemulsions significantly retrain the increase in membrane fluidity caused by AAPH. SDS-PAGE analysis reveals that AAPH induced degradation of membrane proteins, but that nanoemulsions reduce the extension of degradation. Scanning electron microscopy examinations corroborate the interaction between AAPH, nanoemulsions and the RBC membrane bilayer. Our work demonstrates that Punica granatum nanoemulsions are photosafe and protect RBCs against oxidative damage and possible disturbance of the lipid bilayer of biomembranes. Moreover it suggests that these nanoemulsions could be promising new topical products to reduce the effects of sunlight on skin.

Differential erythropoietin action upon cells induced to eryptosis by different agents

Eryptosis is a process by which mature erythrocytes can undergo self-destruction sharing several features with apoptosis. Premature programmed erythrocyte death may be induced by different agents. In this study, we compared mechanisms involved in two eryptotic models (oxidative stress and cell calcium overload) so as to distinguish whether they share signaling pathways and could be prevented by erythropoietin (Epo). Phosphatidylserine (PS) translocation and increased calcium content were common signs in erythrocytes exposed to sodium nitrite plus hydrogen peroxide or calcium ionophore A23187 (CaI), while increased ROS and decreased GSH levels were detected in the oxidative model. Protein kinase activation seemed to be an outstanding feature in eryptosis induced by oxidative stress, whereas phosphatase activation was favored in the CaI model. Cell morphology and membrane protein modifications were also differential signs between both models. Epo was able to prevent cell oxidative imbalance, thus blunting PS translocation. However, the hormone favored intracellular calcium influx which could be the reason why it could not completely counteract the induction of eryptosis. Instead, Epo was unable to inhibit PS externalization in the CaI model. The different mechanisms involved in the eryptotic models may explain the differential action of Epo upon erythrocytes induced to eryptosis by different agents.

A prospective study to assess the predictive value for hereditary spherocytosis using five laboratory tests (cryohemolysis test, eosin-5'-maleimide flow cytometry, osmotic fragility test, autohemolysis test, and SDS-PAGE) on 50 hereditary spherocytosis families in Argentina

This prospective study was carried out to assess the usefulness of five laboratory tests in the diagnosis of hereditary spherocytosis (HS), based on the correlation of erythrocyte membrane protein defects with clinical and laboratory features, and also to determine the membrane protein deficiencies detected in Argentina. Of 116 patients and their family members tested, 62 of them were diagnosed to have HS. The specificity of cryohemolysis (CH) test was 95.2%, and its cut-off value to distinguish HS from normal was 2.8%. For flow cytometry, cut-off points of 17% for mean channel fluorescence (MCF) decrease and 14% coefficient of variation (CV) increase showed 95.9% and 92.2% specificity, respectively. Both tests showed the highest percentages of positive results for diagnosis. Either CH or flow cytometry was positive in 93.5% of patients. In eight patients, flow cytometry was positive only through CV increase. Protein defects were detected in 72.3% of patients; ankyrin and spectrin were the most frequently found deficiencies. The CV of the fluorescence showed significantly higher increases in moderate and severe anemia than in mild anemia (p = 0.003). Severity of anemia showed no other correlation with tests results, type of deficient protein, inheritance pattern, or neonatal jaundice. CH and flow cytometry are easy methods with the highest diagnostic accuracy. Simultaneous reading of mean channel fluorescence (MCF) decrease and CV increase improve diagnostic usefulness of flow cytometry. This test seems to be a reliable predictor of severity. The type of detected protein deficiency has no predictive value for outcome. Predominant ankyrin and spectrin deficiencies agree with reports from other Latin American countries.

HEMATOLOGY: ISSUES IN THE DIALYSIS PATIENT: Erythropoietin Resistance in the Treatment of the Anemia of Chronic Renal Failure

Resistance to erythropoietin therapy is a common complication of the modern management of anemia in chronic kidney disease. Iron deficiency, deficiency of other nutrients, toxins, infections, and inadequate dialysis account for the vast majority of episodes of such resistance.

Aluminum exposure affects transferrin-dependent and -independent iron uptake by K562 cells

Aluminum (Al) and iron (Fe) share several physicochemical characteristics and they both bind to transferrin (Tf), entering the cell via Tf receptors (TfR). Previously, we found similar values of affinity constant for the binding of TfR to Tf carrying either Al or Fe. The competitive interaction between both metals prevented normal Fe incorporation into K562 cells and triggered the upregulation of Fe transport. In the present work we demonstrated that Al modified Fe uptake without affecting the expression of Tf receptors. Both TfR and TfR2 mRNA levels, evaluated by RT-PCR, and TfR antigenic sites, analyzed by flow cytometry, were found unchanged after Al exposure. In turn, Al did induce upregulation of non-Tf bound Fe (NTBI) uptake. This modulation was not due to intracellular Fe decrease since NTBI transport proved not to be regulated by Fe depletion. Unlike its behavior in the presence of Tf, Al was unable to compete with NTBI uptake, suggesting that both metals do not share the same alternative transport pathway. We propose that Al interference with TfR-mediated Fe incorporation might trigger the upregulation of NTBI uptake, an adaptation aimed at incorporating the essential metal required for cellular metabolism without allowing the simultaneous access of a potentially toxic metal.

In vivo effect of aluminium upon the physical properties of the erythrocyte membrane

Aluminium (Al (III)) is a metal with no biological function. Its organic accumulation can lead to toxic effects. To elucidate the in vivo effect of Al (III) upon the rheological properties of the erythrocyte membrane, male adult Wistar rats have been submitted to periodical injections of Al(OH)3 during three months. Significant decreases in haematocrit (34+/-0.37% versus 36+/-0.20%, p<0.0001) and blood haemoglobin concentration (10.7+/-0.15 g/dl versus 12.3+/-0.49 g/dl, p<0.005) have been found. Haemolysis curves shifted towards the left, indicating that erythrocytes became more resistant to hypotonic haemolysis. Significant increments in rigidity index (29.6+/-1.59 versus 9.2+/-0.40, p<0.0001), relative viscosity at native haematocrit (3.6+/-0.03 versus 3.5+/-0.03, p<0.04), and relative viscosity at standard haematocrit (4.5+/-0.06 versus 3.9+/-0.05, p<0.0001) have been observed. The decrease in the erythrocyte aggregate size (1.6+/-0.01 versus 1.7+/-0.01, p<0.002) and the aggregation rate (0.5+/-0.02 versus 0.6+/-0.03, p<0.002) indicated a significantly dropped aggregability process. In conclusion, Al (III) disorganised the erythrocyte membrane by altering its mechanical properties, suggesting a reduction of the middle life of circulating erythrocytes, which could play a major role in the anaemia of these animals.

The distinct erythropoietin functions that promote cell survival and proliferation are affected by aluminum exposure through mechanisms involving erythropoietin receptor

Erythropoietin (Epo) promotes the development of erythroid progenitors by triggering intracellular signals through the binding to its specific receptor (EpoR). Previous results related to the action of aluminum (Al) on erythropoiesis let us suggest that the metal affects Epo interaction with its target cells. In order to investigate this effect on cell activation by the Epo-EpoR complex, two human cell lines with different dependence on Epo were subjected to Al exposure. In the Epo-independent K562 cells, Al inhibited Epo antiapoptotic action and triggered a simultaneous decrease in protein and mRNA EpoR levels. On the other hand, proliferation of the strongly Epo-dependent UT-7 cells was enhanced by long-term Al treatment, in agreement with the upregulation of EpoR expression during Epo starvation. Results provide some clues to the way by which Epo supports cell survival and growth, and demonstrate that not all the intracellular factors needed to guarantee the different signaling pathways of Epo-cell activation are available or activated in cells expressing EpoR. This study then suggests that at least one of the mechanisms by which Al interfere with erythropoiesis might involve EpoR modulation.

Aluminium-induced changes in hemato-biochemical parameters, lipid peroxidation and enzyme activities of male rabbits: protective role of ascorbic acid

For a long time, aluminium (Al) has been considered an indifferent element from a toxicological point of view. In recent years, however, Al has been implicated in the pathogenesis of several clinical disorders, such as dialysis dementia, the fulminant neurological disorder that can develop in patients on renal dialysis. Therefore, the present experiment was carried out to determine the effectiveness of l-ascorbic acid (AA) in alleviating the toxicity of aluminium chloride (AlCl3) on certain hemato-biochemical parameters, lipid peroxidation and enzyme activities of male New Zealand white rabbits. Six rabbits per group were assigned to 1 of 4 treatment groups: 0mg AA and 0mg AlCl3/kg body weight (BW) (control); 40 mg AA/kg BW; 34 mg AlCl3/kg BW (1/25 LD50); 34 mg AlCl3 plus 40 mg AA/kg BW. Rabbits were orally administered their respective doses every other day for 16 weeks. Evaluations were made for lipid peroxidation, enzyme activities and hemato-biochemical parameters. Results obtained showed that AlCl3 significantly (P<0.05) induced free radicals and decreased the activity of glutathione S-transferase (GST) and the levels of sulfhydryl groups (SH groups) in rabbit plasma, liver, brain, testes and kidney. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AlP), acid phosphatase (AcP), and phosphorylase activities were significantly decreased in liver and testes due to AlCl3 administration. While, plasma, liver, testes and brain lactate dehydrogenase (LDH) activities were significantly increased. Contrariwise, the activity of acetylcholinesterase (AChE) was significantly decreased in brain and plasma. Aluminium treatment caused a significant decrease in plasma total lipids (TL), blood haemoglobin (Hb), total erythrocytic count (TEC) and packed cell volume (PCV), and increased total leukocyte count (TLC) and the concentrations of glucose, urea, creatinine, bilirubin and cholesterol. Ascorbic acid alone significantly decreased the levels of free radicals, TL, cholesterol, glucose and creatinine, and increased the activity of GST, SH groups, Hb, TEC and PCV. While, the rest of the tested parameters were not affected. Also, the present study showed that ascorbic acid can be effective in the protection of aluminium-induced toxicity.