Comparison of the effects of deferasirox, deferoxamine, and combination of deferasirox and deferoxamine on an aplastic anemia mouse model complicated with iron overload

Panaxadiol saponin ameliorates ferroptosis in iron-overload aplastic anemia mice and Meg-01 cells by activating Nrf2/HO-1 and PI3K/AKT/mTOR signaling pathway

Panaxadiol saponin (PND) is a latent targeted drug for the treatment of aplastic anemia (AA). In this study, we examined the effects of PND on ferroptosis in iron-overload AA and Meg-01 cells. We utilized RNA-seq to analyze differentially expressed genes in iron-induced Meg-01 cells treated with PND. The effects of PND or combined with deferasirox (DFS) on iron deposition, labile iron pool (LIP), several ferroptosis events, apoptosis, mitochondrial structure, as well as ferroptosis-, Nrf2/HO-1-, and PI3K/AKT/mTOR pathway-related markers in iron-induced Meg-01 cells were examined by Prussian-blue staining, flow cytometer, ELISA, Hoechst 33342 staining, transmission electron microscope, and Western blot assays, respectively. Additionally, an AA mice model with iron overload was established. Then, the blood routine was assessed, and the number of bone marrow-derived mononuclear cells (BMMNCs) in mice was counted. Also, serum iron, ferroptosis events, apoptosis, histology, T lymphocyte percentage, ferroptosis-, Nrf2/HO-1-, and PI3K/AKT/mTOR signaling-related targets in primary megakaryocytes of AA mice with iron overload were assessed by commercial kits, TUNEL staining, hematoxylin and eosin (H&E) staining, Prussian blue staining, flow cytometer, and qRT-PCR analysis, respectively. PND suppressed iron-triggered iron overload, and apoptosis, and ameliorated mitochondrial morphology in Meg-01 cells. Importantly, PND ameliorated ferroptosis-, Nrf2/HO-1-, and PI3K/AKT/mTOR signaling-related marker expressions in iron-induced Meg-01 cells or primary megakaryocytes of AA mice with iron overload. Moreover, PND ameliorated body weight, peripheral blood cell counts, the number of BMMNCs, and histological injury in the iron-overload AA mice. Also, PND improved the percentage of T lymphocytes in the iron-overload AA mice. PND attenuates ferroptosis against iron-overload AA mice and Meg-01 cells via activating Nrf2/HO-1 and PI3K/AKT/mTOR pathway and is a promising novel therapeutic candidate for AA.

Deferasirox versus deferoxamine in managing iron overload in patients with Sickle Cell Anaemia: a systematic review and meta-analysis

OBJECTIVES

To examine the efficacy of deferasirox (DFX) by comparison with deferoxamine (DFO) in managing iron overload in patients with sickle cell anaemia (SCA).

METHODS

Online databases were systematically searched for studies published from January 2007 to July 2022 that had investigated the efficacy of DFX compared with DFO in managing iron overload in patients with SCA.

RESULTS

Of the 316 articles identified, three randomized clinical trials met the inclusion criteria. Meta-analysis of liver tissue iron concentration (LIC) showed that iron overload was not significantly higher in the DFX group compared with DFO group (WMD, -1.61 mg Fe/g dw (95% CI -4.42 to 1.21). However, iron overload as measured by serum ferritin was significantly lower in DFO compared with DFX group (WMD, 278.13 µg/l (95% CI 36.69 to 519.57). Although meta-analysis was not performed on myocardial iron concentration due to incomplete data, the original report found no significant difference between DFX and DFO.

CONCLUSION

While limited by the number of studies included in this meta-analysis, overall, the results tend to show that DFX was as effective as DFO in managing iron overload in patients with SCA.

Differentiation of Yin, Yang and Stasis Syndromes in Severe Aplastic Anemia Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation and Their Correlation with Iron Metabolism, cAMP/cGMP, 17-OH-CS and Thyroxine

Objective

To better understanding and differentiation of traditional Chinese medicine (TCM) syndromes in severe aplastic anemia (SAA) patients undergoing hematopoietic stem cell transplantation (Allo-HSCT) and their correlation with iron metabolism, cAMP/cGMP, 17-OH-CS and thyroxine.

Methods

Eighteen patients with SAA who underwent HSCT were enrolled. The syndrome was evaluated before conditioning and days after stem cell reinfusion (−10d, −1d, +7d, +30d, +60d, and +90d). The correlation of TCM syndrome (Yin, Yang, and stasis) to cyclic nucleotides, 17-OH-CS, thyroxine, and iron metabolism were analyzed and compared to data from normal subjects.

Results

More “Yin deficiency” (n=11, 11/18) syndrome was observed before HSCT, and nearly 61% was complicated with “blood stasis”. After conditioning, the proportion of “kidney Yin and Yang deficiency” increased to 61.6%. Fourteen days after HSCT, the syndrome developed into “Spleen-Kidney Yang Deficiency,” and the stasis score decreased. On +90day, majority patients were diagnosed with “Kidney Yang Deficiency” (35.7%) or “Spleen-Kidney Yang Deficiency” (28.6%), and 88.9% were diagnosed without stasis. The correlation analysis showed that cGMP might represent “Deficient Yang” as well as low total triiodothyronine (T3) and free T3 (FT3). There was also a positive relation between labile plasma iron (LPI), hepcidin, soluble transferrin receptor (sTfR), and “Yin deficiency”, and the last two factors, along with marrow nitric oxide synthase were also positively related to “Stasis” syndrome.

Conclusion

During HSCT, the syndrome evolved from “kidney Yin and Yang deficiency” to “kidney Yang deficiency” or “spleen–kidney Yang deficiency”, and the “stasis” along with “Yin deficiency” syndromes were quickly relieved within 90 days. The changes of cyclic nucleotides, 17-OH-CS, thyroxine, and iron metabolism indexes can be applied for better differentiation of TCM syndrome.

The Effect of Abnormal Iron Metabolism on Osteoporosis

Iron is one of the important trace elements in life activities. Abnormal iron metabolism increases the incidence of many skeletal diseases, especially for osteoporosis. Iron metabolism plays a key role in the bone homeostasis. Disturbance of iron metabolism not only promotes osteoclast differentiation and apoptosis of osteoblasts but also inhibits proliferation and differentiation of osteoblasts, which eventually destroys the balance of bone remodeling. The strength and density of bone can be weakened by the disordered iron metabolism, which increases the incidence of osteoporosis. Clinically, compounds or drugs that regulate iron metabolism are used for the treatment of osteoporosis. The goal of this review summarizes the new progress on the effect of iron overload or deficiency on osteoporosis and the mechanism of disordered iron metabolism on osteoporosis. Explaining the relationship of iron metabolism with osteoporosis may provide ideas for clinical treatment and development of new drugs.

Serum ferritin levels and irregular use of iron chelators predict liver iron load in patients with major beta thalassemia: a cross-sectional study

Aim

To determine whether serum ferritin, liver transaminases, and regularity and type of iron chelation protocol can be used to predict liver iron load as assessed by T2* magnetic resonance imaging (MRI) in patients with beta thalassemia major (TM).

Methods

This cross-sectional study, conducted from March 1, 2014 to March 1, 2015, involved 90 patients with beta TM on regular packed red blood cell transfusion. Liver and cardiac iron load were evaluated with T2* MRI. Compliance with iron-chelating agents, deferoxamine or deferasirox, and regularity of their use, as well as serum ferritin and liver transaminase levels were assessed.

Results

Patients with high serum ferritin were 2.068 times (95% confidence interval 1.26-3.37) more likely to have higher liver or cardiac iron load. High serum aspartate aminotransferases and irregular use of iron chelating agents, but not their type, predicted higher cardiac iron load. In a multiple regression model, serum ferritin level was the only significant predictor of liver and myocardial iron load.

Conclusions

Higher serum ferritin strongly predicted the severity of cardiac and liver iron load. Irregular use of chelator drugs was associated with a higher risk of cardiac and liver iron load, regardless of the type of chelating agent.

Effects of Iron Overload and Oxidative Damage on the Musculoskeletal System in the Space Environment: Data from Spaceflights and Ground-Based Simulation Models

The space environment chiefly includes microgravity and radiation, which seriously threatens the health of astronauts. Bone loss and muscle atrophy are the two most significant changes in mammals after long-term residency in space. In this review, we summarized current understanding of the effects of microgravity and radiation on the musculoskeletal system and discussed the corresponding mechanisms that are related to iron overload and oxidative damage. Furthermore, we enumerated some countermeasures that have a therapeutic potential for bone loss and muscle atrophy through using iron chelators and antioxidants. Future studies for better understanding the mechanism of iron and redox homeostasis imbalance induced by the space environment and developing the countermeasures against iron overload and oxidative damage consequently may facilitate human to travel more safely in space.