Iron toxicity - Its effect on the bone marrow

Diagnosis and management of acquired aplastic anemia in childhood. Guidelines from the Marrow Failure Study Group of the Pediatric Haemato-Oncology Italian Association (AIEOP)

Acquired aplastic anemia (AA) is a rare heterogeneous disorder characterized by pancytopenia and hypoplastic bone marrow. The incidence is 2-3 per million population per year in the Western world, but 3 times higher in East Asia. Survival in severe aplastic anemia (SAA) has improved significantly due to advances in hematopoietic stem cell transplantation (HSCT), immunosuppressive therapy, biologic agents, and supportive care. In SAA, HSCT from a matched sibling donor (MSD) is the first-line treatment. If a MSD is not available, options include immunosuppressive therapy (IST), matched unrelated donor, or haploidentical HSCT. The purpose of this guideline is to provide health care professionals with clear guidance on the diagnosis and management of pediatric patients with AA. A preliminary evidence-based document prepared by a group of pediatric hematologists of the Bone Marrow Failure Study Group of the Italian Association of Pediatric Hemato-Oncology (AIEOP) was discussed, modified and approved during a series of consensus conferences that started online during COVID 19 and continued in the following years, according to procedures previously validated by the AIEOP Board of Directors.

Exploring the bone marrow micro environment in thalassemia patients: potential therapeutic alternatives

Genetic mutations in the β-globin gene lead to a decrease or removal of the β-globin chain, causing the build-up of unstable alpha-hemoglobin. This condition is referred to as beta-thalassemia (BT). The present treatment strategies primarily target the correction of defective erythropoiesis, with a particular emphasis on gene therapy and hematopoietic stem cell transplantation. However, the presence of inefficient erythropoiesis in BT bone marrow (BM) is likely to disturb the previously functioning BM microenvironment. This includes accumulation of various macromolecules, damage to hematopoietic function, destruction of bone cell production and damage to osteoblast(OBs), and so on. In addition, the changes of BT BM microenvironment may have a certain correlation with the occurrence of hematological malignancies. Correction of the microenvironment can be achieved through treatments such as iron chelation, antioxidants, hypoglycemia, and biologics. Hence, This review describes damage in the BT BM microenvironment and some potential remedies.

Incidence of blast phase in myelofibrosis patients according to anemia severity at ruxolitinib start and during therapy

BACKGROUND

Anemia is frequently present in patients with myelofibrosis (MF), and it may be exacerbated by treatment with the JAK2-inhibitor ruxolitinib (RUX). Recently, a relevant blast phase (BP) incidence has been reported in anemic MF patients unexposed to RUX.

METHODS

The authors investigated the incidence of BP in 886 RUX-treated MF patients, included in the "RUX-MF" retrospective study.

RESULTS

The BP incidence rate ratio (IRR) was 3.74 per 100 patient-years (3.74 %p-y). At therapy start, Common Terminology Criteria for Adverse Events grade 3-4 anemia (hemoglobin [Hb] <8 g/dL) and severe sex/severity-adjusted anemia (Hb <8/<9 g/dL in women/men) were present in 22.5% and 25% patients, respectively. IRR of BP was 2.34 in patients with no baseline anemia and reached respectively 4.22, 4.89, and 4.93 %p-y in patients with grade 1, 2, and 3-4 anemia. Considering the sex/severity-adjusted Hb thresholds, IRR of BP was 2.85, 4.97, and 4.89 %p-y in patients with mild/no anemia, moderate, and severe anemia. Transfusion-dependent patients had the highest IRR (5.03 %p-y). Progression-free survival at 5 years was 70%, 52%, 43%, and 27% in patients with no, grade 1, 2, and 3-4 anemia, respectively (p < .001). At 6 months, 260 of 289 patients with no baseline anemia were receiving ruxolitinib, and 9.2% had developed a grade 3-4 anemia. By 6-month landmark analysis, BP-free survival was significantly worse in patients acquiring grade 3-4 anemia (69.3% vs. 88.1% at 5 years, p < .001).

CONCLUSIONS

This study highlights that anemia correlates with an increased risk of evolution into BP, both when present at baseline and when acquired during RUX monotherapy. Innovative anemia therapies and disease-modifying agents are warranted in these patients.

Role of reactive oxygen species in myelodysplastic syndromes

Reactive oxygen species (ROS) serve as typical metabolic byproducts of aerobic life and play a pivotal role in redox reactions and signal transduction pathways. Contingent upon their concentration, ROS production not only initiates or stimulates tumorigenesis but also causes oxidative stress (OS) and triggers cellular apoptosis. Mounting literature supports the view that ROS are closely interwoven with the pathogenesis of a cluster of diseases, particularly those involving cell proliferation and differentiation, such as myelodysplastic syndromes (MDS) and chronic/acute myeloid leukemia (CML/AML). OS caused by excessive ROS at physiological levels is likely to affect the functions of hematopoietic stem cells, such as cell growth and self-renewal, which may contribute to defective hematopoiesis. We review herein the eminent role of ROS in the hematological niche and their profound influence on the progress of MDS. We also highlight that targeting ROS is a practical and reliable tactic for MDS therapy.

Mineral patterns in hair: A decisive factor between reproducible and repeat breeder dairy cows

Reproduction, especially impregnation, is a critical aspect of dairy cow management that directly influences herd milk productivity. We conducted a noninvasive hair mineral assay to compare the mineral profiles of two dairy cow groups: reproducible and repeat breeder, by investigating the levels of 11 essential minerals (Ca, Mg, Na, K, Fe, Cu, Mn, Zn, Cr, Se, and P) and 6 toxic elements (Hg, Pb, Cd, Al, As, and Ni) in both groups. We also conducted principal component and correlation matrix analyses to compare hair mineral patterns between the groups. Compared to their reproducible counterparts, repeat breeder cows had lower levels of Na, K, and Se. However, Fe, Cd, Al, and As levels were higher in repeat breeders than in their reproducible counterparts. The correlation matrix showed notable correlation patterns for each group. Ca, K, and Na levels were positively correlated in reproducible cows, whereas repeat breeder cows showed positive correlations only between Ca and K levels. Se showed positive correlations with Zn only in the reproducible cow group. Negative correlations were not found in the reproducible group, whereas the repeat breeder group exhibited 7 negative correlations. Despite the limitations of hair mineral analysis, this study provided useful insights into the reproductive potential of dairy cows. These findings aid in easing the prediction of repeat breeder occurrences in herds and are expected to facilitate timely mineral supplementation and other interventions to improve overall herd reproduction in dairy farms.

Deferasirox Causes Leukaemia Cell Death through Nrf2-Induced Ferroptosis

Acute lymphoblastic leukaemia (ALL) is the most prevalent cancer in children, and excessive iron buildup resulting from blood transfusions and chemotherapy potentially has a negative impact on treatment outcomes and prognosis in patients with ALL. Therefore, initiating early iron chelation therapy during ALL treatment is a logical approach. Ideally, the selected iron chelator should also possess anti-leukaemia properties. The aim of the present study was to explore the potential impact and underlying mechanism of deferasirox (DFX) in ALL therapy. This study proved that DFX, an iron chelator, is capable of inducing leukaemia cell death through ferroptosis, which is achievable by increasing the expression of acetylated nuclear factor erythroid 2-related factor 2 (NRF2). More specifically, NRF2 acetylation on Lys599 was facilitated by acetyltransferase-p300/CBP. These findings indicate that DFX could serve as a potent adjunctive medication for patients with ALL. Moreover, DFX may offer dual benefits in ALL treatment, functioning as both an iron chelator and NRF2-modulating agent. Further research and clinical trials are necessary to fully elucidate the therapeutic potential of DFX in patients with ALL and incorporate it into treatment protocols.

A comprehensive review on environmental pollutants and osteoporosis: Insights into molecular pathways

A significant problem that has an impact on community wellbeing is environmental pollution. Environmental pollution due to air, water, or soil pollutants might pose a severe risk to global health, necessitating intense scientific effort. Osteoporosis is a common chronic condition with substantial clinical implications on mortality, morbidity, and quality of life. It is closely linked to bone fractures. Worldwide, osteoporosis affects around 200 million people, and every year, there are almost 9 million fractures. There is evidence that certain environmental factors may increase the risk of osteoporosis in addition to traditional risk factors. It is crucial to understand the molecular mechanisms at play because there is a connection between osteoporosis and exposure to environmental pollutants such as heavy metals, air pollutants, endocrine disruptors, metal ions and trace elements. Hence, in this scoping review, we explore potential explanations for the link between pollutants and bone deterioration through deep insights into molecular pathways. Understanding and recognizing these pollutants as modifiable risk factors for osteoporosis would possibly help to enhance environmental policy thereby aiding in the improvement of bone health and improving patient quality of life.

Factors Governing the Erythropoietic Response to Intravenous Iron Infusion in Patients with Chronic Kidney Disease: A Retrospective Cohort Study

BACKGROUND

Limited knowledge exists about factors affecting parenteral iron response. A study was conducted to determine the factors influencing the erythropoietic response to parenteral iron in iron-deficient anaemic patients whose kidney function ranged from normal through all stages of chronic kidney disease (CKD) severity.

METHODS

This retrospective cohort study included parenteral iron recipients who did not receive erythropoiesis-stimulating agents (ESA) between 2017 and 2019. The study cohort was derived from two groups of patients: those managed by the CKD team and patients being optimised for surgery in the pre-operative clinic. Patients were categorized based on their kidney function: Patients with normal kidney function [estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2] were compared to those with CKD stages 3-5 (eGFR < 60 mL/min/1.73 m2). Patients were further stratified by the type of iron deficiency [absolute iron deficiency (AID) versus functional iron deficiency (FID)]. The key outcome was change in hemoglobin (∆Hb) between pre- and post-infusion haemoglobin (Hb) values. Parenteral iron response was assessed using propensity-score matching and multivariate linear regression. The impact of kidney impairment versus the nature of iron deficiency (AID vs. FID) in response was explored.

RESULTS

732 subjects (mean age 66 ± 17 years, 56% females and 87% White) were evaluated. No significant differences were observed in the time to repeat Hb among CKD stages and FID/AID patients. The Hb rise was significantly lower with lower kidney function (non-CKD and CKD1-2; 13 g/L, CKD3-5; 7 g/L; p < 0.001). When groups with different degrees of renal impairment were propensity-score matched according to whether iron deficiency was due to AID or FID, the level of CKD was found not to be relevant to Hb responses [unmatched (∆Hb) 12.1 vs. 8.7 g/L; matched (∆Hb) 12.4 vs. 12.1 g/L in non-CKD and CKD1-2 versus CKD3-5, respectively]. However, a comparison of patients with AID and FID, while controlling for the degree of CKD, indicated that patients with FID exhibited a diminished Hb response regardless of their level of kidney impairment.

CONCLUSION

The nature of iron deficiency rather than the severity of CKD has a stronger impact on Hb response to intravenous iron with an attenuated response seen in functional iron deficiency irrespective of the degree of renal impairment.

Transfusion-dependent non-severe aplastic anemia: characteristics and outcomes in the clinic

Transfusion-dependent non-severe aplastic anemia (TD-NSAA) is a rare condition of bone marrow failure that can persist for a long time or develop into severe aplastic anemia (SAA). Little is known about the clinical and laboratory characteristics, and disease prognosis and outcomes in TD-NSAA patients. The clinical and laboratory data of 124 consecutive TD-NSAA patients in the Chinese Eastern Collaboration Group of Anemia from December 2013 and January 2017 were analyzed retrospectively. In 124 TD-NSAA patients, the median age was 32 years (range: 3-80) and the median disease course was 38 months (range: 3-363). Common complications were iron overload (53/101, 52.5%), liver and kidney dysfunction (42/124, 33.9%), diabetes mellitus/impaired glucose tolerance (24/124, 19.4%), and severe infection (29 cases, 23.4%). 58% of patients (57/124) developed severe aplastic anemia with a median progression time of 24 months (range: 3-216). Patients with absolute neutrophil count (ANC) <0.5×10⁹/L, severe infection, or iron overload had a higher probability of progression to SAA (P=0.022, P=0.025, P=0.001). Patients receiving antithymocyte globulin (ATG) plus Cyclosporin A (CsA) had a higher overall response rate compared to those receiving CsA alone (56.7% vs 19.3%, P < 0.001). The addition of ATG was the favorable factor for efficacy (P=0.003). Fourteen patients developed secondary clonal hematologic disease: eleven patients with paroxysmal nocturnal hemoglobinuria, two patients with myelodysplastic syndromes, and one patient with acute myeloid leukemia, respectively. Ten patients (8.1%) died with a median follow-up of 12 months (range: 3- 36 months). Patients with TD-NSAA usually have a prolonged course of disease, and are prone to be complicated with important organ damage and disease progression to SAA. Intensive immunosuppressive therapy based on ATG might be an appropriate approach for TD-NSAA. Clinical trial registration: http://www.chictr.org.cn/edit.aspx?pid=125480&htm=4, identifier ChiCTR2100045895.

Use of a Waste-Derived Linde Type-A Immobilized in Agarose for the Remediation of Water Impacted by Coal Acid Mine Drainage at Pilot Scale

A new adsorbent based on an immobilized waste-derived LTA zeolite in agarose (AG) has proven to be an innovative and efficient alternative for removing metallic contaminants from water impacted by acid mine drainage (AMD) because the immobilization prevents the solubilization of the zeolite in acidic media and eases its separation from the adsorbed solution. A pilot device was developed containing slices of the sorbent material [AG (1.5%)-LTA (8%)] to be used in a treatment system under an upward continuous flow. High removals of Fe²⁺ (93.45%), Mn²⁺ (91.62%), and Al³⁺ (96.56%) were achieved, thus transforming river water heavily contaminated by metallic ions into water suitable for non-potable use for these parameters, according to Brazilian and/or FAO standards. Breakthrough curves were constructed and the corresponding maximum adsorption capacities (mg/g) (Fe²⁺, 17.42; Mn²⁺, 1.38; Al³⁺, 15.20) calculated from them. Thomas mathematical model was well fitted to the experimental data, indicating the participation of an ion-exchange mechanism in the removal of the metallic ions. The pilot-scale process studied, in addition to being highly efficient in removing metal ions at toxic levels in AMD-impacted water, is linked to the sustainability and circular economy concepts, due to the use as an adsorbent of a synthetic zeolite derived from a hazardous aluminum waste.

Ferritinophagy-mediated iron competition in RUTIs: Tug-of-war between UPEC and host

Uropathogenic Escherichia coli (UPEC) is the main pathogen of recurrent urinary tract infections (RUTIs). Urinary tract infection is a complicated interaction between UPEC and the host. During infection, UPEC can evade the host's immune response and retain in bladder epithelial cells, which requires adequate nutritional support. Iron is the first necessary trace element in life and a key nutritional factor, making it an important part of the competition between UPEC and the host. On the one hand, UPEC grabs iron to satisfy its reproduction, on the other hand, the host relies on iron to build nutritional immunity defenses against UPEC. Ferritinophagy is a selective autophagy of ferritin mediated by nuclear receptor coactivator 4, which is not only a way for the host to regulate iron metabolism to maintain iron homeostasis, but also a key point of competition between the host and UPEC. Although recent studies have confirmed the role of ferritinophagy in the progression of many diseases, the mechanism of potential interactions between ferritinophagy in UPEC and the host is poorly understood. In this paper, we reviewed the potential mechanisms of ferritinophagy-mediated iron competition in the UPEC-host interactions. This competitive relationship, like a tug-of-war, is a confrontation between the capability of UPEC to capture iron and the host's nutritional immunity defense, which could be the trigger for RUTIs. Therefore, understanding ferritinophagy-mediated iron competition may provide new strategies for exploring effective antibiotic alternative therapies to prevent and treat RUTIs.

Poor graft function after haploidentical stem cell transplantation with post-transplant cyclophosphamide

This is a retrospective cohort study of consecutive adult patients who received a haploidentical-SCT (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) in a single centre. Poor graft function (PGF) was defined as the occurrence of either persistent neutropenia (ANC < 0.5 × 10⁹/µL) with poor response to granulocyte colony-stimulating factors (G-CSF) and/or thrombocytopenia (platelets < 20 × 10⁹/L) with transfusion dependence, with complete donor chimerism and without concurrent severe GVHD or underlying disease relapse, during the first 12 months after transplantation. Forty-four (27.5%) out of 161 patients were diagnosed with PGF. Previous CMV reactivation was significantly more frequent in patients with PGF (88.6% versus 73.5%, p = 0.04) and the number of reactivations was also higher in these patients. Besides, early CMV reactivations in the first 6 months post-SCT were also significantly more frequent among patients with PGF (88.6% versus 71.8% p = 0.025). Thirty-two percent of patients with PGF were treated with increasing doses of thrombopoietin-receptor agonists (TRA) and 7 patients were treated with a donor CD34 + selected boost. In total, 93.2% of patients reached adequate peripheral blood counts in a median time of 101 days (range 11-475) after diagnosis. PGF is a frequent complication after haplo-SCT with PT-Cy. CMV reactivation might be the most relevant factor associated to its development. Even when most patients recover peripheral counts with support therapy, there is a group of patients with persistent cytopenias who can effectively be treated with TRA and/or a boost of CD34 + selective cells.

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.

[Graft failure, poor graft function erythroblastopenia: Actualization of definitions, diagnosis and treatment: Guidelines from the SFGM-TC]

In this article, we discuss again the definition, the risk factor and guideline to treat the graft failure, the poor graft function and erythrobalstopenia. Graft failure is a severe but rare complication after hematopoietic cell transplantation (HCT). Despite disparity in the literature, we defined this complication and discussed the factor risks and recommendation for treatment based on new studies. Poor graft function is also a more frequent complication after HCT. New studies will soon be available to prove or not the current recommendation suggested in this article based on therapeutics medicine or cellular therapy. Erythroblastopenia, is a rarer complication post HCT. Despite anticipation for a better choice of compatibility donor/recipient, some patients still suffer from this complication.

Eltrombopag increases the hematopoietic supporting ability of mesenchymal stem/stromal cells

Background

Eltrombopag (EP) is a small molecule that acts directly on hematopoietic stem cells (HSCs) and megakaryocytes to stimulate the hematopoietic process. Mesenchymal stem/stromal cells (MSCs) are key hematopoietic niche regulators.

Objectives

We aimed to determine whether EP has any effect on MSC function and properties (especially on their hematopoietic-supporting ability) and if so, what changes (e.g. genome-wide transcriptomic alterations) are induced in MSC after EP treatment.

Design/Methods

MSCs were isolated from 12 healthy donors and treated with 15 µM and 50 µM of EP for 24 h. The toxicity of the drug on MSCs and their differentiation ability were analyzed, as well as the transcriptomic profile, reactive oxygen species (ROS) and DNA damage and the changes induced in the clonogenic capacity of HSCs.

Results

The results show that EP also modifies MSC functions, decreasing their adipogenic differentiation, increasing the expression of genes involved in hypoxia and other pathways related to oxygen homeostasis, and enhancing their ability to support hematopoiesis in vitro.

Conclusion

Our findings support the use of EP in cases where hematopoiesis is defective, despite its well-known direct effects on hematopoietic cells. Our findings suggest that further studies on the effects of EP on MSCs from patients with aplastic anemia are warranted.

Innovative strategies to improve hematopoietic stem cell transplant outcomes in myelofibrosis

Myelofibrosis (MF) is a clonal myeloproliferative neoplasm characterized by inflammation, marrow fibrosis, and an inherent risk of blastic transformation. Hematopoietic allogeneic stem cell transplant is the only potentially curative therapy for this disease, however, survival gains observed for other transplant indications over the past two decades have not been realized for MF. The role of transplantation may also evolve with the use of novel targeted agents. The chronic inflammatory state associated with MF necessitates pretransplantation assessment of end-organ function. Applying the transplant methodology employed for other myeloid disorders to patients with MF fails to acknowledge differences in the underlying disease pathophysiology. Limited understanding of the causes of poor transplant outcomes in this cohort has prevented refinement of transplant eligibility criteria in MF. There is increasing evidence of heterogeneity in molecular disease grade, beyond the clinical manifestations which have traditionally guided transplant timing. Exploring the physiological consequences of disease chronicity unique to MF, acknowledging the heterogeneity in disease grade, and using advanced prognostic models, molecular diagnostics and other organ function diagnostic tools, we present an innovative review of strategies with the potential to improve transplant outcomes in this disease. Larger, prospective studies which consider the impact of molecular-based disease grade are needed for MF transplantation.

3-Aminopyridine Salicylidene: A Sensitive and Selective Chemosensor for the Detection of Cu(II), Al(III), and Fe(III) with Application to Real Samples

Interest in developing selective and sensitive metal sensors for environmental, biological, and industrial applications is mounting. The goal of this work was to develop a sensitive and selective sensor for certain metal ions in solution. The goal was achieved via (i) preparing the sensor ((E)-2-((pyridine-3-ylimino)methyl)phenol) (3APS) using microwave radiation in a short time and high yield and (ii) performing spectrophotometric titrations for 3APS with several metal ions. 3APS, a Schiff base, was prepared in 5 min and in a high yield (95%) using microwave-assisted synthesis. The compound was characterized by FTIR, XRD, NMR, and elemental analysis. Spectrophotometric titration of 3APS was performed with Al(III), Ba(II), Cd(II), Co(II), Cu(II), Fe(III), Mn(II), Ni(II), and Zn(II). 3APS showed good abilities to detect Al(III) and Fe(III) ions fluorescently and Cu(II) ion colorimetrically. The L/M stoichiometric ratio was 2:1 for Cu(II) and 1:1 for Al(III) and Fe(III). Low detection limits (μg/L) of 324, 20, and 45 were achieved for Cu(II), Al(III), and Fe(III), respectively. The detection of aluminum was also demonstrated in antiperspirant deodorants, test strips, and applications in secret writing. 3APS showed high fluorescent selectivity for Al(III) and Fe(III) and colorimetric selectivity towards Cu(II) with detection limits lower than corresponding safe drinking water guidelines.

Iron Deposition and Ferroptosis in the Spleen in a Murine Model of Acute Radiation Syndrome

Total body irradiation (TBI) can result in death associated with hematopoietic insufficiency. Although radiation causes apoptosis of white blood cells, red blood cells (RBC) undergo hemolysis due to hemoglobin denaturation. RBC lysis post-irradiation results in the release of iron into the plasma, producing a secondary toxic event. We investigated radiation-induced iron in the spleens of mice following TBI and the effects of the radiation mitigator captopril. RBC and hematocrit were reduced ~7 days (nadir ~14 days) post-TBI. Prussian blue staining revealed increased splenic Fe3+ and altered expression of iron binding and transport proteins, determined by qPCR, western blotting, and immunohistochemistry. Captopril did not affect iron deposition in the spleen or modulate iron-binding proteins. Caspase-3 was activated after ~7–14 days, indicating apoptosis had occurred. We also identified markers of iron-dependent apoptosis known as ferroptosis. The p21/Waf1 accelerated senescence marker was not upregulated. Macrophage inflammation is an effect of TBI. We investigated the effects of radiation and Fe3+ on the J774A.1 murine macrophage cell line. Radiation induced p21/Waf1 and ferritin, but not caspase-3, after ~24 h. Radiation ± iron upregulated several markers of pro-inflammatory M1 polarization; radiation with iron also upregulated a marker of anti-inflammatory M2 polarization. Our data indicate that following TBI, iron accumulates in the spleen where it regulates iron-binding proteins and triggers apoptosis and possible ferroptosis.

Unraveling the interplay between iron homeostasis, ferroptosis and extramedullary hematopoiesis

Iron participates in myriad processes necessary to sustain life. During the past decades, great efforts have been made to understand iron regulation and function in health and disease. Indeed, iron is associated with both physiological (e.g., immune cell biology and function and hematopoiesis) and pathological (e.g., inflammatory and infectious diseases, ferroptosis and ferritinophagy) processes, yet few studies have addressed the potential functional link between iron, the aforementioned processes and extramedullary hematopoiesis, despite the obvious benefits that this could bring to clinical practice. Further investigation in this direction will shape the future development of individualized treatments for iron-linked diseases and chronic inflammatory disorders, including extramedullary hematopoiesis, metabolic syndrome, cardiovascular diseases and cancer.

Deferasirox in the management of iron overload in patients with myelofibrosis treated with ruxolitinib: The multicentre retrospective RUX-IOL study

Deferasirox (DFX) is used for the management of iron overload (IOL) in many haematological malignancies including myelofibrosis (MF). The 'RUX-IOL' study retrospectively collected 69 MF patients treated with ruxolitinib (RUX) and DFX for IOL to assess: safety, efficacy in term of iron chelation response (ICR) and erythroid response (ER), and impact on overall survival of the combination therapy. The RUX-DFX therapy was administered for a median time of 12.4 months (interquartile range 3.1-71.2). During treatment, 36 (52.2%) and 34 (49.3%) patients required RUX and DFX dose reductions, while eight (11.6%) and nine (13.1%) patients discontinued due to RUX- or DFX-related adverse events; no unexpected toxicity was reported. ICR and ER were achieved by 33 (47.8%) and 32 patients (46.4%) respectively. Thirteen (18.9%) patients became transfusion-independent. Median time to ICR and ER was 6.2 and 2 months respectively. Patients achieving an ER were more likely to obtain an ICR also (p = 0.04). In multivariable analysis, the absence of leukocytosis at baseline (p = 0.02) and achievement of an ICR at any time (p = 0.02) predicted improved survival. In many MF patients, the RUX-DFX combination provided ICR and ER responses that correlated with improved outcome in the absence of unexpected toxicities. This strategy deserves further clinical investigation.

Efficacy of Recombinant Human Thrombopoietin for the Treatment of Secondary Failure of Platelet Recovery After Allogeneic HSCT

Secondary failure of platelet recovery (SFPR) is a life-threatening complication that may affect up to 20% of patients after allogeneic hematopoietic stem cell transplantation (HSCT). In this study, to evaluate the efficacy of recombinant human thrombopoietin (rhTPO), we retrospectively analyzed 29 patients who received continuous rhTPO for the treatment of SFPR. Overall response and complete response were observed in 24 (82.8%) patients and 10 (34.5%) patients, at a median time of 21.5 days (range, 3-41 days) and 39.5 days (range, 7-53 days) after initiation of rhTPO treatment, respectively. Among the responders, the probability of keeping overall response and complete response at 1 year after response was 77.3% and 80.0%, respectively. In multivariate analysis, higher CD34⁺ cells (≥3 × 10⁶/kg) infused during HSCT (HR: 7.22, 95% CI: 1.53-34.04, P = 0.01) and decreased ferritin after rhTPO treatment (HR: 6.16, 95% CI: 1.18-32.15, P = 0.03) were indicated to associate with complete response to rhTPO. Importantly, rhTPO was well tolerated in all patients without side effects urging withdrawal and clinical intervention. The results of this study suggest that rhTPO may be a safe and effective treatment for SFPR.

From Biology to Clinical Practice: Iron Chelation Therapy With Deferasirox

Iron chelation therapy (ICT) has become a mainstay in heavily transfused hematological patients, with the aim to reduce iron overload (IOL) and prevent organ damage. This therapeutic approach is already widely used in thalassemic patients and in low-risk Myelodysplastic Syndrome (MDS) patients. More recently, ICT has been proposed for high-risk MDS, especially when an allogeneic bone marrow transplantation has been planned. Furthermore, other hematological and hereditary disorders, characterized by considerable transfusion support to manage anemia, could benefit from this therapy. Meanwhile, data accumulated on how iron toxicity could exacerbate anemia and other clinical comorbidities due to oxidative stress radical oxygen species (ROS) mediated by free iron species. Taking all into consideration, together with the availability of approved oral iron chelators, we envision a larger use of ICT in the near future. The aim of this review is to better identify those non-thalassemic patients who can benefit from ICT and give practical tips for management of this therapeutic strategy.

Research advances on haploidentical hematopoietic stem cell transplantation in the treatment of severe aplastic anemia in children

Haploidentical hematopoietic stem cell transplantation is a recommended alternative therapy for children with severe aplastic anemia who lack a human leukocyte antigen (HLA)-identical sibling donor and do not respond well to immunosuppressive therapy; however, due to non-identical HLA, the patients may have donor-specific anti-HLA antibody, which may lead to a relatively high incidence rate of poor graft function. Compared with HLA-identical transplantation, conditioning regimen for haploidentical transplantation still needs to be explored. This article reviews the detection and treatment of donor-specific anti-HLA antibody, the selection of conditioning regimen, and the mechanism and treatment of poor graft function in haploidentical hematopoietic stem cell transplantation.

Iron Toxicity and Chelation Therapy in Hematopoietic Stem Cell Transplant

Many patients with hematologic malignancies receive RBC transfusion support, which often causes systemic and tissue iron toxicity. Because of their compromised bone marrow function, hematopoietic stem cell transplant (HSCT) recipients are especially vulnerable to excess iron levels. Iron toxicity may compromise transplant engraftment and eventually promote relapse by mediating oxidative and genotoxic stress in hematopoietic stem cells (HSCs) and further impairing the already dysfunctional bone marrow microenvironment in HSCT recipients. Iron toxicity is thought to be primarily mediated by its ability to induce reactive oxygen species and trigger inflammation. Elevated iron levels in the bone marrow can decrease the number of HSCs and progenitor cells, as well as their clonogenic potential, alter mesenchymal stem cell differentiation, and inhibit the expression of chemokines and adhesion molecules involved in hematopoiesis. In vivo, in vitro, and clinical studies support the concept that iron chelation therapy may limit iron toxicity in the bone marrow and promote hematologic improvement and engraftment in HSCT recipients. This review will provide an overview of the current knowledge of the detrimental impact of iron toxicity in the setting of HSCT in patients with hematologic malignancies and the use of iron restriction approaches to improve transplant outcome.

Synthesis and characterization of novel tricyanofuran hydrazone probe: solvatochromism, density-functional theory calculation and selective fluorescence, and colorimetric determination of iron (III)

A tricyanofuran hydrazone (TCFH) spectroscopic probe was produced to visually recognize Fe(III) ions in aqueous environments. The synthesis was started by reacting tricyanofuran with 4-aminophenol diazonium chloride. All the synthesized compounds were characterized by spectroscopic analyses. TCFH showed distinctive solvatochromic behaviour in various organic polar solvents due to intramolecular charge transfer. Its behaviour towards sensing Fe(III) was studied using ultraviolet-visible spectrophotometry. The sensing behaviours of the proposed probe for other metal ions, namely Co(II), Cr(III), Mg(II), Pb(II), Cd(II), Ba(II), Hg(II), Mn(II), Ni(II), Cu(II), Zn(II), Ca(II), Al(III), Na(I) and K(I), were also investigated, but no spectral changes were observed, indicating the probe's potential use as a highly selective and Fe(III)-sensitive colorimetric and fluorescent chemical sensor. The TCFH probe using EtOH/H₂ O (5:1; v/v) served as a colorimetric and fluorescent chemosensor for identification of Fe(III) by the naked eye owing to both its high sensitivity and selectivity towards Fe(III) compared with the other examined metal ions. The proposed TCFH probe can therefore be utilized as an effective spectroscopic sensor for Fe(III). Both colorimetric and fluorescence recognition of the analyte depended on the concentration of Fe(III) ions and was accomplished at a pH of 7. A rapid colour change from yellow to red occurred when an aqueous solution of Fe(III) ions was added. The intensity of the colour increased at higher Fe(III) concentrations. Cyclic voltammetry measurements in the dimethylformamide solvent indicated a nonreversible redox potential. This study also explained the possible mechanisms for both solvatochromism and the detection of Fe(III) through TCFH-Fe(III) complex formation. The binding constant of the generated TCFH-Fe(III) complex was explored. Computational modelling was conducted to explain the deprotonation-triggered changes that occur in the photophysical properties of TCFH dyes.

Hematopoietic stem cell function in β-thalassemia is impaired and is rescued by targeting the bone marrow niche

Hematopoietic stem cells (HSCs) are regulated by signals from the bone marrow (BM) niche that tune hematopoiesis at steady state and in hematologic disorders. To understand HSC-niche interactions in altered nonmalignant homeostasis, we selected β-thalassemia, a hemoglobin disorder, as a paradigm. In this severe congenital anemia, alterations secondary to the primary hemoglobin defect have a potential impact on HSC-niche cross talk. We report that HSCs in thalassemic mice (th3) have an impaired function, caused by the interaction with an altered BM niche. The HSC self-renewal defect is rescued after cell transplantation into a normal microenvironment, thus proving the active role of the BM stroma. Consistent with the common finding of osteoporosis in patients, we found reduced bone deposition with decreased levels of parathyroid hormone (PTH), which is a key regulator of bone metabolism but also of HSC activity. In vivo activation of PTH signaling through the reestablished Jagged1 and osteopontin levels correlated with the rescue of the functional pool of th3 HSCs by correcting HSC-niche cross talk. Reduced HSC quiescence was confirmed in thalassemic patients, along with altered features of the BM stromal niche. Our findings reveal a defect in HSCs in β-thalassemia induced by an altered BM microenvironment and provide novel and relevant insight for improving transplantation and gene therapy approaches.

Advances in the understanding of poor graft function following allogeneic hematopoietic stem-cell transplantation

Poor graft function (PGF) following allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a life-threatening complication and is characterized by bilineage or trilineage blood cell deficiency and hypoplastic marrow with full chimerism. With the rapid development of allo-HSCT, especially haploidentical-HSCT, PGF has become a growing concern. The most common risk factors illustrated by recent studies include low dose of infused CD34+ cells, donor-specific antibody, cytomegalovirus infection, graft versus host disease (GVHD), iron overload and splenomegaly, among others. Because of the poor prognosis of PGF, it is crucial to uncover the underlying mechanism, which remains elusive. Recent studies have suggested that the bone marrow microenvironment may play an important role in the pathogenesis of PGF. Deficiency and dysfunction of endothelial cells and mesenchymal stem cells, elevated reactive oxygen species (ROS) levels, and immune abnormalities are believed to contribute to PGF. In this review, we also discuss recent clinical trials that evaluate the safety and efficacy of new strategies in patients with PGF. CD34+-selected stem-cell boost (SCB) is effective with an acceptable incidence of GVHD, despite the need for a second donation. Alternative strategies including the applications of mesenchymal stem cells, N-acetyl-l-cysteine (NAC), and eltrombopag have shown favorable outcomes, but further large-scale studies are needed due to the small sample sizes of the recent clinical trials.

Suppression of compensatory erythropoiesis in hemolytic disease of the fetus and newborn due to intrauterine transfusions

BACKGROUND

Infants with severe hemolytic disease of the fetus and newborn often require 1 or multiple intrauterine transfusions to treat fetal anemia. Intrauterine transfusions may have an inhibiting effect on fetal and neonatal erythropoiesis.

OBJECTIVE

To quantify the effect of 1 or multiple intrauterine transfusions on the fetal erythropoiesis by assessing the fetal reticulocyte counts in a population with severe hemolytic disease of the fetus and newborn.

STUDY DESIGN

This was an observational cohort study in infants admitted to the Leiden University Medical Center who received 1 or multiple intrauterine transfusions for hemolytic disease of the fetus and newborn caused by (Rh)D or Kell antibodies and were born between January 2005 and December 2018.

RESULTS

A total of 235 patients were included, of whom 189 were patients with D-mediated hemolytic disease of the fetus and newborn and 46 with Kell-mediated hemolytic disease of the fetus and newborn. Absolute fetal reticulocyte count in D-mediated hemolytic disease of the fetus and newborn declined exponentially over the course of consecutive intrauterine transfusions, with a 62% decline after 1 intrauterine transfusion (95% confidence interval, 56-67). A similar exponential decline was observed in Kell-mediated hemolytic disease of the fetus and newborn, with 32% (95% confidence interval, 19-45) decline after 1 intrauterine transfusion. This decline was not associated with the varying gestational age at the time of the first intrauterine transfusion or the total number of intrauterine transfusions. The number of red blood cell transfusions for postnatal anemia was greater for infants with D and Kell-mediated hemolytic disease of the fetus and newborn with >2 intrauterine transfusions (median of 3 [interquartile range, 2-3] vs 2 [interquartile range, 1-3], P=.035, in D-mediated disease and median of 2 [interquartile range, 1-2] vs 1 [interquartile range, 1-1], P<.001, in Kell-mediated disease). Infants born after >2 intrauterine transfusions less often required exchange transfusion in D-mediated hemolytic disease of the fetus and newborn (19/89 [21%] vs 31/100 [31%], P=.039), compared with infants with 1-2 intrauterine transfusions.

CONCLUSION

Treatment with intrauterine transfusions causes an exponential decrease in fetal reticulocyte counts in both D- and Kell-mediated hemolytic disease of the fetus and newborn. Suppression of the compensatory erythropoiesis leads to prolonged postnatal anemia and an increased requirement of red blood cell transfusions after birth.

High serum ferritin levels in newly diagnosed patients with myelodysplastic syndromes are associated with greater symptom severity

We examined the association between serum ferritin (SF) levels and patient-reported functional aspects and symptoms, as measured by the EORTC QLQ-C30, in newly diagnosed patients with myelodysplastic syndromes (MDS). Analysis was conducted on 497 MDS patients who were classified in two groups based on the SF value of 1000 ng/mL. Clinically relevant differences of patient-reported functional and symptom scales were evaluated and classified as small, medium and large, based on established thresholds. Multivariable linear regression analysis was performed to account for potential confounding factors. Patients with SF of ≥ 1000 ng/mL reported statistically significant and clinically relevant worse outcomes across various health domains. Dyspnea was the symptom indicating the largest difference and mean scores of patients with higher and lower SF levels were 40 and 24.3, respectively (p = 0.005), indicating a large clinically relevant difference (Δ = 15.7). Further research is needed to better understand the relationship between SF levels and specific health-related quality of life domains.

Controversies on the Consequences of Iron Overload and Chelation in MDS

Many patients with MDS are prone to develop systemic and tissue iron overload in part as a consequence of disease-immanent ineffective erythropoiesis. However, chronic red blood cell transfusions, which are part of the supportive care regimen to correct anemia, are the major source of iron overload in MDS. Increased systemic iron levels eventually lead to the saturation of the physiological systemic iron carrier transferrin and the occurrence of non-transferrin-bound iron (NTBI) together with its reactive fraction, the labile plasma iron (LPI). NTBI/LPI-mediated toxicity and tissue iron overload may exert multiple detrimental effects that contribute to the pathogenesis, complications and eventually evolution of MDS. Until recently, the evidence supporting the use of iron chelation in MDS was based on anecdotal reports, uncontrolled clinical trials or prospective registries. Despite not fully conclusive, these and more recent studies, including the TELESTO trial, unravel an overall adverse action of iron overload and therapeutic benefit of chelation, ranging from improved hematological outcome, reduced transfusion dependence and superior survival of iron-loaded MDS patients. The still limited and somehow controversial experimental and clinical data available from preclinical studies and randomized trials highlight the need for further investigation to fully elucidate the mechanisms underlying the pathological impact of iron overload-mediated toxicity as well as the effect of classic and novel iron restriction approaches in MDS. This review aims at providing an overview of the current clinical and translational debated landscape about the consequences of iron overload and chelation in the setting of MDS.

Cyclophosphamide induces a significant increase in iron content in the liver and spleen of mice

Objective:

Oxidative stress is one of the major mechanisms of cyclophosphamide (CPX)-induced toxicities. However, it is unknown how CPX induces oxidative stress. Based on the available information, we speculated that CPX could increase iron content in the tissues and then induce oxidative stress.

Method:

We tested this hypothesis by investigating the effects of CPX on iron and ferritin contents, expression of transferrin receptor 1 (TfR1), ferroportin 1 (Fpn1), iron regulatory proteins (IRPs), hepcidin, and nuclear factor erythroid 2-related factor-2 (Nrf2) in the liver and spleen, and also on reticulocyte count, immature reticulocyte fraction, and hemoglobin (Hb) in the blood in c57/B6 mouse.

Results:

We demonstrated that CPX could induce a significant increase in iron contents and ferritin expression in the liver and spleen, notably inhibit erythropoiesis and Hb synthesis and lead to a reduction in iron usage. The reduced expression in TfR1 and Fpn1 is a secondary effect of CPX-induced iron accumulation in the liver and spleen and also partly associated with the suppressed IRP/iron-responsive element system, upregulation of hepcidin, and downregulation of Nrf2.

Conclusions:

The reduced iron usage is one of the causes for iron overload in the liver and spleen and the increased tissue iron might be one of the mechanisms for CPX to induce oxidative stress and toxicities.

Assessment of metal concentrations in oysters and shrimp from Atlantic Coast of the Democratic Republic of the Congo

Oysters and shrimp are abundant and commonly consumed seafood by the indigenous population of the Kongo central region of the Democratic Republic of the Congo (DRC). Literature reviews suggest that no data were available for the metal concentrations in these species. Consequently, the purpose of this study is to determine the metal concentrations in tissues of oysters (Egeria congica) and shrimp (Macrobrachium spp., Parapenaeus spp., Penaeus spp.) collected in November 2017 from the Atlantic Ocean Coast of DRC in the territory of Muanda. Metal levels in the seafood species studied here were put into context using international regulation for human consumption set by the Food and Agriculture Organization (FAO), Canadian Food Inspection Agency (CFIA), European Union (EU), and World Health Organization (WHO). Our results demonstrated that the concentration of heavy metals varied considerably between sampling sites and analyzed species (P < 0.05), with the values (in mg kg1) ranged between 0.05-0.41, 0.03-2.25, Collapse

Key Words

• Atlantic Ocean
• Bioaccumulation
• Congo DR
• Environmental pollution
• Environmental risk assessment
• Environmental science
• Heavy metal
• Oysters
• Shrimp
• Water pollution
• Water quality

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Affiliation(s)

Robert B. Suami University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo University of Kinshasa (UNIKIN), Faculty of Pharmaceutical Sciences, B.P. 212, Kinshasa XI, Democratic Republic of the Congo
Dhafer Mohammed M. Al Salah Department F.-A. Forel for Environmental and Aquatic Sciences and Institute of Environmental Sciences, School of Earth and Environmental Sciences, Faculty of Science, University of Geneva, Uni Carl Vogt, 66 Boulevard Carl-Vogt, Geneva 4, CH-1211, Switzerland King Abdulaziz City for Science and Technology, Joint Centers of Excellence Program, Prince Turki the 1st Street, Riyadh, 11442, Saudi Arabia
César D. Kabala University of Kinshasa (UNIKIN), Faculty of Pharmaceutical Sciences, B.P. 212, Kinshasa XI, Democratic Republic of the Congo
J.-P. Otamonga Université Pédagogique Nationale (UPN). Croisement Route de Matadi et Avenue de la Libération. Quartier Binza/UPN, B.P. 8815, Kinshasa, République Démocratique du Congo
Crispin K. Mulaji University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo
Pius T. Mpiana University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo
John W. Poté University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo Department F.-A. Forel for Environmental and Aquatic Sciences and Institute of Environmental Sciences, School of Earth and Environmental Sciences, Faculty of Science, University of Geneva, Uni Carl Vogt, 66 Boulevard Carl-Vogt, Geneva 4, CH-1211, Switzerland Université Pédagogique Nationale (UPN). Croisement Route de Matadi et Avenue de la Libération. Quartier Binza/UPN, B.P. 8815, Kinshasa, République Démocratique du Congo

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Cystathionine β-synthase (CBS) deficiency suppresses erythropoiesis by disrupting expression of heme biosynthetic enzymes and transporter

The reduced iron usage induced by the suppression of erythropoiesis is a major cause of the systemic iron overload in CBS knockout (CBS^−/−) mice. However, the relevant mechanisms are unknown. Here, we examined changes in granulocyte/erythroid cell ratios, iron content, and expression of iron-metabolism proteins, including; two key enzymes involved in the heme biosynthetic pathway, ALAS2 (delta-aminolevulinate synthase 2) and FECH (ferrochelatase), a heme exporter from the cytosol and mitochondria, FLVCR (feline leukemia virus subgroup C cellular receptor) as well as EPO (erythropoietin), EPOR (erythropoietin receptor) and HIF-2α (hypoxia inducible factor-2 subunit α), in the blood, bone marrow or liver of CBS^−/− (homozygous), CBS^+/− (heterozygous) and CBS^+/+ (Wild Type) mice. Our findings demonstrate that CBS deficiency can induce a significant reduction in the expression of ALAS2, FECH, FLVCR, HIF-2α, EPO, and EPOR as well as an increase in interleukin-6 (IL-6), hepcidin and iron content in the blood, bone marrow or liver of mice. We conclude that the suppression of erythropoiesis is mainly due to the CBS deficiency-induced disruption in the expression of heme biosynthetic enzymes and heme-transporter.

Excessive Reactive Iron Impairs Hematopoiesis by Affecting Both Immature Hematopoietic Cells and Stromal Cells

Iron overload is the accumulation of excess iron in the body that may occur as a result of various genetic disorders or as a consequence of repeated blood transfusions. The surplus iron is then stored in the liver, pancreas, heart and other organs, which may lead to chronic liver disease or cirrhosis, diabetes and heart disease, respectively. In addition, excessive iron may impair hematopoiesis, although the mechanisms of this deleterious effect is not entirely known. In this study, we found that ferrous ammonium sulfate (FeAS), induced growth arrest and apoptosis in immature hematopoietic cells, which was mediated via reactive oxygen species (ROS) activation of p38MAPK and JNK pathways. In in vitro hematopoiesis derived from embryonic stem cells (ES cells), FeAS enhanced the development of dysplastic erythroblasts but inhibited their terminal differentiation; in contrast, it had little effect on the development of granulocytes, megakaryocytes, and B lymphocytes. In addition to its directs effects on hematopoietic cells, iron overload altered the expression of several adhesion molecules on stromal cells and impaired the cytokine production profile of these cells. Therefore, excessive iron would affect whole hematopoiesis by inflicting vicious effects on both immature hematopoietic cells and stromal cells.

A Review of Metal Exposure and Its Effects on Bone Health

The presence of metals in the environment is a matter of concern, since human activities are the major cause of pollution and metals can enter the food chain and bioaccumulate in hard and soft tissues/organs, which results in a long half-life of the metal in the body. Metal intoxication has a negative impact on human health and can alter different systems depending on metal type and concentration and duration of metal exposure. The present review focuses on the most common metals found in contaminated areas (cadmium, zinc, copper, nickel, mercury, chromium, lead, aluminum, titanium, and iron, as well as metalloid arsenic) and their effects on bone tissue. Both the lack and excess of these metals in the body can alter bone dynamics. Long term exposure and short exposure to high concentrations induce an imbalance in the bone remodeling process, altering both formation and resorption and leading to the development of different bone pathologies.