Novel approach to reactive oxygen species in nontransfusion-dependent thalassemia

The interactions between ineffective erythropoiesis and ferroptosis in β-thalassemia

In Guangxi, Hainan, and Fujian Province in southern China, β-thalassemia is a frequent monogenic hereditary disorder that is primarily defined by hemolytic anemia brought on by inefficient erythropoiesis. It has been found that ineffective erythropoiesis in β-thalassemia is closely associated with a high accumulation of Reactive oxygen species, a product of oxidative stress, in erythroid cells. During recent years, ferroptosis is an iron-dependent lipid peroxidation that involves abnormalities in lipid and iron metabolism as well as reactive oxygen species homeostasis. It is a recently identified kind of programmed cell death. β-thalassemia patients experience increased iron release from reticuloendothelial cells and intestinal absorption of iron, ultimately resulting in iron overload. Additionally, the secretion of Hepcidin is inhibited in these patients. What counts is both ineffective erythropoiesis and ferroptosis in β-thalassemia are intricately linked to the iron metabolism and Reactive oxygen species homeostasis. Consequently, to shed further light on the pathophysiology of β-thalassemia and propose fresh ideas for its therapy, this paper reviews ferroptosis, ineffective erythropoiesis, and the way they interact.

Deferiprone, an iron chelator, alleviates platelet hyperactivity in patients with β-thalassaemia/HbE

Background

Hyperfunctional platelets play important roles in thromboembolism in patients with β-thalassaemia/ haemoglobin E (β-thal/HbE). Our previous study revealed ex vivo inhibitory effects of deferiprone on normal platelets. Herein, we aimed to investigate the in vivo effects on platelets in patients with β-thal/HbE.

Methods

A prospective, self-controlled clinical study on 30 patients with β-thal/HbE who had received therapeutic deferiprone (20.8-94.5 mg/kg/day) was conducted. The study included a 4-week washout period followed by 4 and 12 weeks of deferiprone treatment. Platelet aggregation was performed by a turbidimetric method. Levels of deferiprone and soluble platelet (sP)-selectin in serum were measured by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) kit, respectively.

Results

The washout period significantly enhanced platelet hyperactivity both in patients who had undergone splenectomy and in those who had not. At 2 hours following the administration of a single dose of deferiprone, platelet sensitivity to ADP and arachidonic acid was significantly reduced. The inhibitory effects of deferiprone were gradually increased over the period of 4 and 12 weeks. Deferiprone also depressed sP-selectin levels, but the effect was stable over longer follow-up periods. Correlation analysis demonstrated the relationship between serum levels of deferiprone, sP-selectin, and platelet activities induced by ADP and arachidonic acid.

Conclusion

We first demonstrated the in vivo antiplatelet effect and benefit of short-term treatment of deferiprone in patients with β-thal/HbE. The impact on thrombotic outcomes deserves further study.

Dynamic Thiol-Disulfide Homeostasis in Children With β-Thalassemia Trait

In children with β-thalassemia (β-thal) trait, tissue damage occurs with oxidative stress due to oxygen free radicals and reactive oxygen species (ROS) production. Dynamic thiol-disulfide homeostasis (DTDH) is one of the most important indicators showing the pro-oxidant/antioxidant status in the body. In this study, we aimed to examine the status of DTDH by measuring native thiol, disulfide, and total thiol levels in children with β-thal trait. The study included 40 children with β-thal trait and 30 healthy controls (matched by age and gender). The DTDH parameters were measured by an automated method and results were compared between the groups. The levels of native thiol, total thiol, and disulfide in children with β-thal trait group were statistically significantly higher than the control group (p < 0.001). There was no significant difference in disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol levels between the groups. In addition, there was no correlation between hemoglobin (Hb) and serum ferritin levels with the markers of DTDH in children with β-thal trait. In our study, a significant increase was found in native thiol, total thiol, and disulfide levels in response to oxidative stress in children with β-thal trait compared to the healthy control group. Disulfide levels of the children with β-thal trait were higher than the control group, showing oxidative stress is high in β-thal trait. Accordingly, it increases the native thiol and total thiol capacity as compensation.

Antioxidant Activity and Oxidative Stress Status in Maternal Serum of β-thalassemic Mothers Carrying β-thalassemic Major and Normal Fetuses

Objectiveβ-thalassemia is a genetic disorder characterized by reduction or absence of β-globin chain with mutations in both copies (β-thalassemia major) or in one copy (β-thalassemia minor). Pregnancies in β- thalassemic carrier women are considered symptom free but have risk of inheriting β-thalassemic fetuses. Current study was designed to compare oxidative stress and antioxidants status in maternal serum from β-thalassemic minor mothers having β-thalassemic major and normal fetuses. Method: We investigated paraoxonase (PON1) and arylesterase (ARE) activities along with malondialdehyde (MDA) and reactive oxygen species (ROS) in maternal serum of β-thalassemic carrier women. Results: PON1 and ARE activities were found to be significantly decreased, whereas the concentration of MDA and ROS were significantly increased in β-thalassemic minor mothers with β-thalassemic major fetuses. Conclusion: The study concludes that redox imbalance in β-thalassemic trait mothers carrying thalassemic fetuses is higher than in mothers carrying normal fetuses.

Thalassemia Patients from Baluchistan in Pakistan Are Infected with Multiple Hepatitis B or C Virus Strains

There are an estimated 2,000 children with β-thalassemia in the province Baluchistan of Pakistan. These children are at high risk of acquiring transfusion-transmitted infections (TTIs) due to their need of regular blood transfusions for survival. Therefore, we investigated the frequencies of TTIs among these multi-transfused patients in a region where the WHO guidelines for blood safety are not always followed. Sera from 400 children (mean age 7.7 ± 4.70 years) treated at two thalassemia centers in Baluchistan were investigated for TTIs. Eleven (2.8%) were hepatitis B surface antigen positive, and 72 (18.3%) had anti-hepatitis C virus (HCV), two of which were infected with both viruses. Only 22% of the children had been reached by the program for universal hepatitis B virus (HBV) vaccination which started in 2004. Half (51%) of the HCV infected had also been HBV infected. The HBV- and HCV-infected patients were older and had received more blood transfusions than the uninfected patients (P < 0.001). Molecular characterization of the viral strains revealed the presence of several genetically different strains in at least three HBV- and seven HCV-infected children. This is the first study to demonstrate infections with multiple HBV or HCV strains simultaneously infecting thalassemia patients. These may become the source for new emerging recombinant viruses of unknown virulence. The high prevalence of anti-HCV-positive children, and the presence of HBV infections among children who should have been vaccinated, highlights an urgent need for improvements of blood safety in this region of Pakistan.

Ameliorating potency of Chenopodium album Linn. and vitamin C against mercuric chloride-induced oxidative stress in testes of Sprague Dawley rats

BACKGROUND

Mercury has been documented as an industrial risk that posed a serious danger to human health. Mercury exposure results in oxidative stress that may lead to the pathogenesis of male reproductive dysfunction. The present study investigated the ameliorating potential of Chenopodium album L. and vitamin C against mercuric chloride-induced oxidative deterioration of reproductive functions in adult male rats.

METHODS

Group 1 (control) received saline. Group 2 received Mercury (0.15 mg/kg b.w, i.p) dissolved in distilled water. Groups 3 and 4 were given oral gavage of vitamin C (200 mg/kg b.w) and the ethanolic extract of C. album (200 mg/kg b.w) respectively, along with Mercury (0.15 mg/kg b.w, i.p). Group 5 was treated only with C. album (200 mg/kg b.w). After 30 days of the treatment, the rats were dissected and their testicular tissue and the cauda epididymis were used for biochemical analysis while blood plasma was used for protein determination.

RESULTS

The applied dose-treatment of Mercury-induced oxidative stress in the testis and cauda epididymis tissues of the rats was apparent by a noteworthy decrease in total protein, CAT, SOD, POD, and GST values while there was increase in ROS and TBARS levels. Furthermore, Mercury decreases daily sperm production and enhanced sperm DNA damage as noticeable by an increase in the head and tail length of comets and decrease in intact DNA. There was no significant effect on the body weight and the weight of the reproductive tissues. Treatment with C. album significantly ameliorated the total protein, ROS, and TBARS content. Similarly, the level of CAT, SOD, POD, and GST was significantly improved and the daily sperm production was significantly increased. Furthermore, C. album administration significantly protected Mercury-induced sperm DNA damage. The results of the extract treatment group were compared with those of vitamin C in detoxifying the oxidative stress and restoring the sperm parameters.

CONCLUSION

C. album showed protection against Mercury-induced oxidative stress by ameliorating antioxidant enzyme activity, daily sperm production, and DNA damage in rat testes. This suggests that C. album could be beneficial against toxicity induced by an environmental toxicant.

Serum ferritin level as an early indicator of metabolic dysregulation in young obese adults - a cross-sectional study

The aim of this study was to investigate the relationship between serum ferritin level and antioxidative status and metabolic dysregulation in young adult obese population. This cross-sectional study included 300 subjects of either sex, grouped as obese and non-obese subjects. The body mass index, total iron binding capacity, fasting blood glucose, superoxide dismutase activity, and levels of serum ferritin, iron, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, glutathione, and vitamin C were estimated. Analysis showed a significant alteration in all the parameters in obese adults. The correlation of ferritin level and body mass index showed a positive correlation (r = -0.81, p < 0.001, respectively) with levels of fasting blood glucose, superoxide dismutase, total cholesterol, low-density lipoprotein cholesterol, and triglyceride in obese individuals, whereas an insignificant correlation with vitamin C and glutathione level was observed in obese individuals. The significant positive correlation of ferritin level with the metabolic parameters and some antioxidative parameters in obese individuals signifies the development of metabolic disorders. Therefore, estimation of serum ferritin level will be an important early indicator for the risk of developing metabolic disorders in young adults.

Transferrin receptor 2 is a potential novel therapeutic target for β-thalassemia: evidence from a murine model

β-thalassemias are genetic disorders characterized by anemia, ineffective erythropoiesis, and iron overload. Current treatment of severe cases is based on blood transfusion and iron chelation or allogeneic bone marrow (BM) transplantation. Novel approaches are explored for nontransfusion-dependent patients (thalassemia intermedia) who develop anemia and iron overload. Here, we investigated the erythropoietin (EPO) receptor partner, transferrin receptor 2 (TFR2), as a novel potential therapeutic target. We generated a murine model of thalassemia intermedia specifically lacking BM Tfr2: because their erythroid cells are more susceptible to EPO stimulation, mice show improved erythropoiesis and red blood cell morphology as well as partial correction of anemia and iron overload. The beneficial effects become attenuated over time, possibly due to insufficient iron availability to sustain the enhanced erythropoiesis. Germ line deletion of Tfr2, including haploinsufficiency, had a similar effect in the thalassemic model. Because targeting TFR2 enhances EPO-mediated effects exclusively in cells expressing both receptors, this approach may have advantages over erythropoiesis-stimulating agents in the treatment of other anemias.

Elevations of Thrombotic Biomarkers in Hemoglobin H Disease

BACKGROUND

Thalassemia is a group of hereditary hemoglobinopathies caused by decreased or absent synthesis of α and/or β globin chains. Studies have shown that hypercoagulability and thrombosis are common clinical symptoms in β-thalassemia, especially β-thalassemia intermedia, but little is known about in α-thalassemia. This study aims to examine phosphatidylserine (PS) levels, platelet activation, and coagulation markers in splenectomized (S) and nonsplenectomy (NS) patients with hemoglobin (Hb) H disease.

METHODS

The NS group comprised 20 patients (median age 15.0 years, range, 14-16.5 years), and the S group consisted of 11 patients (median age 16.4 years, range, 14-19.9 years) with Hb H disease; the control group consisted of 20 normal subjects. Hematological parameters were collected. Flow cytometry was used to measure PS exposure on red blood cells. The levels of intercellular adhesive molecule (ICAM)-1, tumor necrosis factor α (TNFα), β-thromboglobulin (TG) and prothrombin fragment 1 + 2 (F1.2) were determined using ELISA test kits.

RESULTS

Significant increases in the levels of PS, ICAM-1, TNFα, β-TG, and F1.2 were observed in both patient groups compared to normal controls (p < 0.01).

CONCLUSION

This observation indicates blood coagulation, endothelial injury, chronic low-grade inflammation, platelet activation, and thrombin generation are present in Hb H disease; these findings merit further assessment in a larger prospective cohort to establish possible links with thrombotic manifestations.

Protective effects of GABA against metabolic and reproductive disturbances in letrozole induced polycystic ovarian syndrome in rats

Background

PCOs is a heterogeneous disorder with anovulation/oligo ovulation usually taken as oligo menorrhoea or amenorrhoea, hyperandrogenemia, hirsutism, acne, androgen alopecia and polycystic ovaries as the key diagnostic feathers. The study was undertaken to investigate the possible protective and ameliorating effects of GABA in Letrozole induced PCOS model in rats by targeting insulin resistance.

Methods

PCOs in Adult female rat was induced by the daily gastric administration of letrozole (1 mg/kg/day) in CMC (0.5%) for 36 days. Rats were given metformin (2 mg/kg), GABA (100 mg/kg/day) and GABA (500 mg/kg/day) along with letrozole. One group severed as vehicle control. On the 37 day, the animals were euthanized, and anthropometrical, biochemical (glucose, insulin, lipids, testosterone, Estradiol, Progesterone, oral glucose tolerance test, total protein content in ovary, cholesterol level, triglyceride, HDL, LDL), Antioxidants (CAT, POD, GSR, ROS, GSH, TBARS), and histopathological evaluation of ovaries were carried out. Daily colpocytological examination was also carried out until the termination.

Results

Both the doses of GABA significantly reduced body weight, body mass index and testosterone. While the levels of CAT, SOD, POD and Estradiol (E₂) were significantly increased in the both doses of GABA. A favourable lipid profile, normal glucose tolerance, and decreased in the percentage of estrus smears were observed. Histopathological examination of ovary revealed a decreased in the number of cystic follicles, and decreased in the adipocytes respectively. The effects observed with GABA were comparable to that with metformin.

Conclusion

The results suggest that GABA treatment has shown protective effect in PCOs and provide beneficial effect either by reducing insulin resistance or by inducing antioxidant defence mechanisms.

The Impact of Iron Overload in Acute Leukemia: Chronic Inflammation, But Not the Presence of Nontransferrin Bound Iron is a Determinant of Oxidative Stress

In the literature, studies on the oxidant effects of nontransferrin bound iron [NTBI (eLPI assay)] during chemotherapy of acute lymphoblastic leukemia and acute myeloblastic leukemia are lacking. We established NTBI and oxidative stress determinants (OSD), iron parameters, high-sensitive C-reactive protein (hs-CRP) levels, liver tests, cumulative chemotherapeutic doses, and transfused blood in 36 children with acute leukemia throughout chemotherapy. These parameters were determined at the beginning and end of chemotherapy blocks (11 time points) and in 20 healthy children using enzyme-linked immunosorbent assay, and colorimetric and fluorometric enzymatic methods. In acute lymphoblastic leukemia, NTBI, OSD, and hs-CRP were higher than controls at 4/11, 7/11, and 9/11 time points (P<0.05). At 3 time points, NTBI and OSD concurrently increased. Ferritin, soluble transferrin receptor, serum iron, and transferrin saturation were higher than in controls at 5 to 11/11 time points (P<0.05). Those with NTBI had higher iron parameters than those without NTBI (P<0.05), but showed similar OSD, hs-CRP, liver enzymes, cumulative chemotherapeutics, and transfused blood (P>0.05). OSD did not correlate with NTBI, but correlated with hs-CRP. In conclusion, NTBI is a poor predictor of OSD in acute leukemia possibly because of the heterogeneity of NTBI and chronic inflammation. Further studies are needed to delineate the pathophysiology of these diseases.

Mean Platelet Volume in Heterozygous Beta Thalassaemia

BACKGROUND/AIM

It is not known why cerebrovascular and cardiovascular ischaemic events are less frequently observed in heterozygous beta thalassaemia (HBT) patients than in the general population. However, we previously reported that serum levels of some platelet function markers, i.e. soluble CD40 ligand and soluble P-selectin, are lower in patients with HBT than in controls. A high mean platelet volume (MPV) is an indicator of in vivo platelet activation and may indicate a tendency to thrombosis. We investigated whether MPV is lower in HBT patients than in controls.

METHODS

Forty-eight patients with HBT were compared with 51 controls matched for gender, age, and BMI for MPV in a cross-sectional study.

RESULTS

The MPV was within the normal range and higher in the HBT group (9.64 ± 1.20 vs. 9.07 ± 082 fL, p = 0.006). The 2 groups were similar in terms of atherosclerosis risk factors and medications. After linear regression analysis, the MPV was correlated with HBT, sensitive CRP, and BMI.

CONCLUSION

The higher MPV in patients with HBT could indicate platelet activation, and this may represent a dilemma. Higher MPV in the HBT group might have resulted from higher sympathetic nervous system activity, mild ineffective erythropoiesis, and haemolysis.

New strategies to target iron metabolism for the treatment of beta thalassemia

Iron is one of the most abundant elements in the Earth and a fundamental component of enzymes and other proteins that participate in a wide range of biological processes. As the human body has no mechanisms to eliminate the excess of iron, its metabolism needs to be tightly controlled in order to avoid all the sequelae associated with high iron levels. Iron overload is the main cause of morbidity and mortality in beta thalassemia. The master regulator of iron homeostasis, hepcidin, is chronically repressed in this disorder, leading to increased intestinal iron absorption and consequent iron overload. Many groups have focused on obtaining a better understanding of the pathways involved in iron regulation. New molecules have recently been synthesized and used in animal models of dysregulated iron metabolism, demonstrating their ability to target and reduce iron load. Antisense oligonucleotides, as well as lipid nanoparticle-formulated small interfering RNAs and minihepcidins peptides, are novel agents that have already proved to be efficient in modulating iron metabolism in mouse models and are therefore promising candidates for the treatment of patients affected by iron disorders.