Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.
Humans ; Mice ; Animals ; Transcranial Magnetic Stimulation ; Alzheimer Disease/therapy* ; Cognitive Dysfunction/therapy* ; Cognition ; Sulfur ; Iron ; Iron-Sulfur Proteins ; Mitochondrial Proteins

Iron is an essential element for living organisms that plays critical roles in the process of bacterial growth and metabolism. However, it remains to be elucidated whether piuB encoding iron-uptake factor is involved in iron uptake and pathogenicity of Xanthomonas axonopodis pv. glycines (Xag). To investigate the function of piuB, we firstly generated a piuB deletion mutant (ΔpiuB) by homologous recombination. Compared with the wild-type, the piuB mutant exhibited significantly reduced growth and virulence in host soybean. The mutant displayed markedly increased siderophore secretory volume, and its sensitivity to Fe³⁺, Cu²⁺, Zn²⁺ and Mn²⁺ was significantly enhanced. Additionally, the H₂O₂ resistance, exopolysaccharide yield, biofilm formation, and cell mobility of ΔpiuB were significantly diminished compared to that of the wild-type. The addition of exogenous Fe³⁺ cannot effectively restore the above characteristics of ΔpiuB. However, expressing piuB in trans rescued the properties lost by ΔpiuB to the levels in the wild-type. Taken together, our results demonstrated that PiuB is a potential factor for Xag to assimilate Fe³⁺, and is necessary for Xag to be pathogenic in host soybean.
Iron ; Glycine max ; Virulence ; Xanthomonas axonopodis/genetics* ; Hydrogen Peroxide

Cerebral hypoxia often brings irreversible damage to the central nervous system, which seriously endangers human health. It is of great significance to further explore the mechanism of hypoxia-associated brain injury. As a programmed cell death, ferroptosis mainly manifests as cell death caused by excessive accumulation of iron-dependent lipid peroxides. It is associated with abnormal glutathione metabolism, lipid peroxidation and iron metabolism, and is involved in the occurrence and development of various diseases. Studies have found that ferroptosis plays an important role in hypoxia-associated brain injury. This review summarizes the mechanism of ferroptosis, and describes its research progress in cerebral ischemia reperfusion injury, neonatal hypoxic-ischemic brain damage, obstructive sleep apnea-induced brain injury and high-altitude hypoxic brain injury.
Humans ; Infant, Newborn ; Ferroptosis ; Apoptosis ; Hypoxia-Ischemia, Brain ; Brain Injuries ; Iron ; Reperfusion Injury

Macrophages are important immune effector cells with significant plasticity and heterogeneity in the body immune system, and play an important role in normal physiological conditions and in the process of inflammation. It has been found that macrophage polarization involves a variety of cytokines and is a key link in immune regulation. Targeting macrophages by nanoparticles has a certain impact on the occurrence and development of a variety of diseases. Due to its characteristics, iron oxide nanoparticles have been used as the medium and carrier for cancer diagnosis and treatment, making full use of the special microenvironment of tumors to actively or passively aggregate drugs in tumor tissues, which has a good application prospect. However, the specific regulatory mechanism of reprogramming macrophages using iron oxide nanoparticles remains to be further explored. In this paper, the classification, polarization effect and metabolic mechanism of macrophages were firstly described. Secondly, the application of iron oxide nanoparticles and the induction of macrophage reprogramming were reviewed. Finally, the research prospect and difficulties and challenges of iron oxide nanoparticles were discussed to provide basic data and theoretical support for further research on the mechanism of the polarization effect of nanoparticles on macrophages.
Humans ; Macrophages/metabolism* ; Cytokines ; Inflammation ; Neoplasms/metabolism* ; Nanoparticles ; Magnetic Iron Oxide Nanoparticles ; Tumor Microenvironment

OBJECTIVE: To investigate the possible causes of abnormal hemoglobin electrophoresis results. METHODS: The hemoglobin electrophoresis results of 5 696 patients in the First Affiliated Hospital of Chengdu Medical College from September 2018 to July 2021 were collected, and the abnormal results and clinical significance were analyzed. RESULTS: The results of 486 patients (accounting for 8.53%) were abnormal, of which 300 cases had increased HbA2, 135 cases had decreased HbA2, 44 cases had increased F alone, and 7 cases had abnormal hemoglobin bands. Among the 486 patients, 246 patients were thalassemia gene positive (the positive rate was 50.62%), including 29 cases of α thalassemia, 208 cases of β thalassemia and 9 cases of αβ thalassemia. Among the patients with elevated HbA2, 68.67% were detected β thalassemia, 3.00% αβ thalassemia, 9.33% were suspected to be caused by macrocytosis, 6.33% by thyroid dysfunction, and 12.67% by uncertainty of the method. Among the patients with reduced HbA2, 21.48% were detected α thalassemia, 60.00% iron deficiency anemia, 8.15% were suspected to be caused by thyroid dysfunction, and 10.37% by uncertainty of the method. Among the patients with elevated F alone, the results of thalassemia gene detection were negative, 40.91% of them were suspected to be caused by macrocytosis, 27.27% by hereditary persistence of fetal hemoglobin, 29.55% by special physiological condition of pregnant women, and 2.27% by hyperthyroidism. Abnormal hemoglobin bands were detected in 7 patients, including 4 cases of hemoglobin D, 2 cases of hemoglobin E, and 1 case of hemoglobin J. CONCLUSION Thalassemia, iron deficiency anemia, macrocytosis such as megaloblastic anemia and non-severe aplastic anemia, thyroid dysfunction, hereditary persistence of fetal hemoglobin, abnormal hemoglobin diseases, the uncertainty of the method are all important causes of abnormal hemoglobin electrophoresis results. In clinical work, the patient's indicators should be comprehensively analyzed to determine the possible cause.
Humans ; Female ; Pregnancy ; beta-Thalassemia/genetics* ; Anemia, Iron-Deficiency ; Fetal Hemoglobin/analysis* ; alpha-Thalassemia ; Blood Protein Electrophoresis ; Hemoglobin A2/analysis* ; Hemoglobins, Abnormal/analysis*

Postmenopausal osteoporosis is a kind of degenerative disease, also described as "invisible killer." Estrogen is generally considered as the key hormone for women to maintain bone mineral content during their lives. Iron accumulation refers to a state of human serum ferritin that is higher than the normal value but less than 1000 μg/L. It has been found that iron accumulation and osteoporosis could occur simultaneously with the decrease in estrogen level after menopause. In recent years, many studies indicated that iron accumulation plays a vital role in postmenopausal osteoporosis, and a significant correlation has been found between iron accumulation and fragility fractures. In this review, we summarize and analyze the relevant literature including randomized controlled trials, systematic reviews, and meta-analyses between January 1996 and July 2022. We investigate the mechanism of the effect of iron accumulation on bone metabolism and discuss the relationship of iron accumulation, osteoporosis, and postmenopausal fragility fractures, as well as the main clinical treatment strategies. We conclude that it is necessary to pay attention to the phenomenon of iron accumulation in postmenopausal women with osteoporosis and explore the in-depth mechanism of abnormal bone metabolism caused by iron accumulation, in order to facilitate the discovery of effective therapeutic targets for postmenopausal osteoporosis.
Humans ; Female ; Osteoporotic Fractures ; Osteoporosis, Postmenopausal/drug therapy* ; Postmenopause ; Osteoporosis ; Bone Density ; Estrogens ; Iron/therapeutic use*

The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB.
Siderophores/metabolism* ; Iron/metabolism* ; Mycobacterium tuberculosis/metabolism* ; Cryoelectron Microscopy ; Adenosine Triphosphate/metabolism* ; ATP-Binding Cassette Transporters

Apoptosis ; Autophagy ; Ferroptosis ; Iron/metabolism* ; Sequestosome-1 Protein/metabolism* ; Ubiquitin-Specific Proteases/metabolism*

Ferroptosis is defined as an iron-dependent regulated form of cell death driven by lipid peroxidation. In the past decade, it has been implicated in the pathogenesis of various diseases that together involve almost every organ of the body, including various cancers, neurodegenerative diseases, cardiovascular diseases, lung diseases, liver diseases, kidney diseases, endocrine metabolic diseases, iron-overload-related diseases, orthopedic diseases and autoimmune diseases. Understanding the underlying molecular mechanisms of ferroptosis and its regulatory pathways could provide additional strategies for the management of these disease conditions. Indeed, there are an expanding number of studies suggesting that ferroptosis serves as a bona-fide target for the prevention and treatment of these diseases in relevant pre-clinical models. In this review, we summarize the progress in the research into ferroptosis and its regulatory mechanisms in human disease, while providing evidence in support of ferroptosis as a target for the treatment of these diseases. We also discuss our perspectives on the future directions in the targeting of ferroptosis in human disease.
Humans ; Ferroptosis ; Autoimmune Diseases ; Cardiovascular Diseases ; Iron ; Musculoskeletal Diseases

OBJECTIVE: To investigate whether the acetaldehyde dehydrogenase 2 specific activator, Alda-1, can alleviate brain injury after cardiopulmonary resuscitation (CPR) by inhibiting cell ferroptosis mediated by acyl-CoA synthetase long-chain family member 4/glutathione peroxidase 4 (ACSL4/GPx4) pathway in swine. METHODS: Twenty-two conventional healthy male white swine were divided into Sham group (n = 6), CPR model group (n = 8), and Alda-1 intervention group (CPR+Alda-1 group, n = 8) using a random number table. The swine model of CPR was reproduced by 8 minutes of cardiac arrest induced by ventricular fibrillation through electrical stimulation in the right ventricle followed by 8 minutes of CPR. The Sham group only experienced general preparation. A dose of 0.88 mg/kg of Alda-1 was intravenously injected at 5 minutes after resuscitation in the CPR+Alda-1 group. The same volume of saline was infused in the Sham and CPR model groups. Blood samples were collected from the femoral vein before modeling and 1, 2, 4, 24 hours after resuscitation, and the serum levels of neuron specific enolase (NSE) and S100 β protein were determined by enzyme-linked immunosorbent assay (ELISA). At 24 hours after resuscitation, the status of neurologic function was evaluated by neurological deficit score (NDS). Thereafter, the animals were sacrificed, and brain cortex was harvested to measure iron deposition by Prussian blue staining, malondialdehyde (MDA) and glutathione (GSH) contents by colorimetry, and ACSL4 and GPx4 protein expressions by Western blotting. RESULTS: Compared with the Sham group, the serum levels of NSE and S100β after resuscitation were gradually increased over time, and the NDS score was significantly increased, brain cortical iron deposition and MDA content were significantly increased, GSH content and GPx4 protein expression in brain cortical were significantly decreased, and ACSL4 protein expression was significantly increased at 24 hours after resuscitation in the CPR model and CPR+Alda-1 groups, which indicated that cell ferroptosis occurred in the brain cortex, and the ACSL4/GPx4 pathway participated in this process of cell ferroptosis. Compared with the CPR model group, the serum levels of NSE and S100 β starting 2 hours after resuscitation were significantly decreased in the CPR+Alda-1 group [NSE (μg/L): 24.1±2.4 vs. 28.2±2.1, S100 β (ng/L): 2 279±169 vs. 2 620±241, both P < 0.05]; at 24 hours after resuscitation, the NDS score and brain cortical iron deposition and MDA content were significantly decreased [NDS score: 120±44 vs. 207±68, iron deposition: (2.61±0.36)% vs. (6.31±1.66)%, MDA (μmol/g): 2.93±0.30 vs. 3.68±0.29, all P < 0.05], brain cortical GSH content and GPx4 expression in brain cortical was significantly increased [GSH (mg/g): 4.59±0.63 vs. 3.51±0.56, GPx4 protein (GPx4/GAPDH): 0.54±0.14 vs. 0.21±0.08, both P < 0.05], and ACSL4 protein expression was significantly decreased (ACSL4/GAPDH: 0.46±0.08 vs. 0.85±0.13, P < 0.05), which indicated that Alda-1 might alleviate brain cortical cell ferroptosis through regulating ACSL4/GPx4 pathway. CONCLUSIONS Alda-1 can reduce brain injury after CPR in swine, which may be related to the inhibition of ACSL4/GPx4 pathway mediated ferroptosis.
Male ; Animals ; Swine ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Ferroptosis ; Brain Injuries ; Glutathione ; Cardiopulmonary Resuscitation ; Ligases ; Iron