Role of Ferroptosis in Bone Homeostasis and Traditional Chinese Medicine Intervention： A Review / 中国实验方剂学杂志

Osteoporosis （OP） is a systemic metabolic bone disease characterized by bone microstructure degeneration and bone mass loss， which has a high prevalence and disability rate. Effective prevention and treatment of OP is a major difficulty in the medical community. The nature of OP is that multiple pathological factors lead to the imbalance of human bone homeostasis maintained by osteoblasts and osteoclasts. Ferroptosis is a non-apoptotic cell death pathway， and its fundamental cause is cell damage caused by iron accumulation and lipid peroxidation. Studies have shown that ferroptosis is involved in and affects the occurrence and development of OP， which leads to OP by mediating the imbalance of bone homeostasis. Ferroptosis is an adjustable form of programmed cell death. The intervention of ferroptosis can regulate the damage degree and death process of osteoblasts and osteoclasts， which is beneficial to maintain bone homeostasis， slow down the development process of OP， improve the clinical symptoms of patients， reduce the risk of disability， and improve their quality of life. However， there are few studies on ferroptosis in OP. Traditional Chinese medicine （TCM） is a medical treasure with unique characteristics and great application value in China. It has been widely used in China and has a long history. It has the multi-target and multi-pathway advantages in the treatment of OP， with high safety， few toxic and side effects， and low treatment cost， and has a significant effect in clinical application. The intervention of TCM in ferroptosis to regulate bone homeostasis may be a new direction for the prevention and treatment of OP in the future. This article summarized the regulatory mechanisms related to ferroptosis， discussed the role of ferroptosis in bone homeostasis， and reviewed the current status and progress of active ingredients in TCM compounds and monomers in the regulation of OP through ferroptosis， so as to provide a theoretical basis for the participation of TCM in the prevention and treatment of OP in the future.

Iron accumulation and its impact on osteoporotic fractures in postmenopausal women / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

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.

PLA2G6-related parkinsonism:clinical and genetic characteristics of 6 cases and literature review / 中华神经科杂志

Objective:To elucidate the clinical and genetic characteristics of PLA2G6-related parkinsonism. Methods:The clinical, imaging and genetic data of 6 patients with PLA2G6-related parkinsonism admitted to Peking Union Medical College Hospital from January 2015 to December 2022 were retrospectively collected and analyzed. The prognosis was followed up through phone call. Results:There were 3 male and 3 female patients, and the age of disease onset was (24.3±5.4) years. Phenotypically, 5 of them had dystonia-parkinsonism (DP) with obvious atrophy of cerebellum and 1 presented as early-onset Parkinson′s disease (EOPD) with no brain structural abnormality. Only 1 patient presented with abnormal brain iron deposition. All of the patients were partially responsive to levodopa. Three cases underwent levodopa challenge test with the objective levodopa responsiveness varied from 10.3% and 10.6% in 2 DP patients, to 77.0% in 1 EOPD patient. Levodopa-induced dyskinesias were present in 4 of them, and all appeared within the first year since the initiation of dopaminergic treatment. Two patients underwent bilateral deep brain stimulation (DBS) of subthalamic nucleus and globus pallidus internus respectively, albeit revealed poor outcome. Genetically, 8 PLA2G6 variants were identified. Two of them were found to be novel (c.1973A>G and exon2 heterozygous deletion), and the most frequent variant was the c.991G>T mutation which was detected in 4 patients. Conclusions:The phenotype of PLA2G6-related parkinsonism is complex. Cerebellar atrophy is a frequent magnetic resonance imaging feature. Levodopa responsiveness tends to depend on the clinical phenotype, and EOPD is better than DP. DBS might not be promising in DP patients with obvious cerebral atrophy. The c.991G>T mutation is the most frequent mutation, suggesting a common founder effect.

Ferroptosis:Mechanism and Role in Malignant Tumors / 中国医学科学院学报

Ferroptosis is a new type of programmed cell death different from other cell death pathways such as apoptosis,autophagy,necrosis,and pyroptosis in terms of initiation,mechanisms,and molecular characteristics.As the accumulation of phospholipid hydroperoxides is the hallmark of ferroptosis,the balance between oxidative damage and antioxidant defense is critical to the regulatory mechanism of ferroptosis.In cancer,the upregulation of antioxidant defense pathways can inhibit ferroptosis,thereby promoting cancer cells to survive the oxidative stress and develop drug resistance.This review systematically introduces the main features and regulatory mechanisms of ferroptosis.In addition,we summarize the role of ferroptosis in the progression and drug resistance of malignant tumors,providing novel implications for further research on the pathogenesis of malignant tumors and discovery of new targets for anti-cancer therapy.

Iron accumulation induces osteoporosis by disrupting Wnt signaling pathway / 中华内分泌代谢杂志

The specimens of femur from wild-type mice(WT) of 6 months and Hepcidin-knockout(KO) mice of 6 months(iron accumulation model) were obtained for Micro-CT examination. Western blot and co-immunoprecipitation were used to detect the changes of related parameters in Wnt signaling pathway. Compared with wild-type mice, the bone mass in Hepcidin-KO mice was significantly decreased, the binding of β-catenin to FOXO3a increased, and binding of β-catenin to TCF4/TCF7L2 decreased in bone tissue, without significant changes in the expression of β-catenin, TCF4/TCF7L2, and FOXO3a. These results suggest that iron accumulation may affect bone formation through interfering with canonical Wnt/β-catenin signaling pathway, finally leading to osteoporosis.

Iron accumulation induces osteoporosis by disrupting Wnt signaling pathway / 中华内分泌代谢杂志

The specimens of femur from wild-type mice(WT) of 6 months and Hepcidin-knockout(KO) mice of 6 months ( iron accumulation model ) were obtained for Micro-CT examination. Western blot and co-immunoprecipitation were used to detect the changes of related parameters in Wnt signaling pathway. Compared with wild-type mice, the bone mass in Hepcidin-KO mice was significantly decreased, the binding ofβ-catenin to FOXO3a increased, and binding of β-catenin to TCF4/TCF7L2 decreased in bone tissue, without significant changes in the expression ofβ-catenin, TCF4/TCF7L2, and FOXO3a. These results suggest that iron accumulation may affect bone formation through interfering with canonical Wnt/β-catenin signaling pathway, finally leading to osteoporosis.[Summary] The specimens of femur from wild-type mice(WT) of 6 months and Hepcidin-knockout(KO) mice of 6 months ( iron accumulation model ) were obtained for Micro-CT examination. Western blot and co-immunoprecipitation were used to detect the changes of related parameters in Wnt signaling pathway. Compared with wild-type mice, the bone mass in Hepcidin-KO mice was significantly decreased, the binding ofβ-catenin to FOXO3a increased, and binding of β-catenin to TCF4/TCF7L2 decreased in bone tissue, without significant changes in the expression ofβ-catenin, TCF4/TCF7L2, and FOXO3a. These results suggest that iron accumulation may affect bone formation through interfering with canonical Wnt/β-catenin signaling pathway, finally leading to osteoporosis.

A Patient with Beta-Propeller Protein-Associated Neurodegeneration: Treatment with Iron Chelation Therapy

We present a case of beta-propeller protein-associated neurodegeneration, a form of neurodegeneration with brain iron accumulation. The patient harbored a novel mutation in the WDR45 gene. A detailed video and description of her clinical condition are provided. Her movement disorder phenomenology was characterized primarily by limb stereotypies and gait dyspraxia. The patient's disability was advanced by the time iron-chelating therapy with deferiprone was initiated, and no clinical response in terms of cognitive function, behavior, speech, or movements were observed after one year of treatment.

Botulinum Toxin-A Injection in the Treatment of Spasticity in a Infantile-Onset Neurodegeneration With Brain Iron Accumulation: A Case Report

Pantothenate kinase-associated neurodegeneration (PKAN) is a neurodegenerative disorder characterized by iron accumulation in the globus pallidus (GP) of the brain (neurodegeneration with brain iron accumulation [NBIA]), which is characterized by dystonia and spasticity resulting in postural difficulties. A 33-month-old boy was admitted with a pronounced gait disturbance. Marked hypertonicity in the patient's both calf muscles was noted, resulting in waddling with repeated slip-falls. NBIA was suspected by high T2 intensity in the GP on brain MRI, then it was confirmed by detecting PANK2 mutation. Botulinum toxin-A injection was administered to both calf muscles. After 2 weeks, a decrease in spasticity and an increase in range of motion were observed, and consequently, an increase in the patient's gait stability with both heels touching the ground, enabling him to walk straight independently. A definitive treatment for NBIA has not been established, and a symptomatic therapy is currently the mainstay of treatment in this case. This is the first case report of botulinum toxin injection for treatment of gait disturbance caused by spasticity in an infantile-onset PKAN.

A diagnostic approach for neurodegeneration with brain iron accumulation: clinical features, genetics and brain imaging / Uma orientação diagnóstica para neurodegeneração com acúmulo cerebral de ferro: aspectos clínicos, genéticos e de neuroimagem

ABSTRACT Neurodegeneration with brain iron accumulation (NBIA) represents a heterogeneous and complex group of inherited neurodegenerative diseases, characterized by excessive iron accumulation, particularly in the basal ganglia. Common clinical features of NBIA include movement disorders, particularly parkinsonism and dystonia, cognitive dysfunction, pyramidal signs, and retinal abnormalities. The forms of NBIA described to date include pantothenase kinase-associated neurodegeneration (PKAN), phospholipase A2 associated neurodegeneration (PLAN), neuroferritinopathy, aceruloplasminemia, beta-propeller protein-associated neurodegeneration (BPAN), Kufor-Rakeb syndrome, mitochondrial membrane protein-associated neurodegeneration (MPAN), fatty acid hydroxylase-associated neurodegeneration (FAHN), coenzyme A synthase protein-associated neurodegeneration (CoPAN) and Woodhouse-Sakati syndrome. This review is a diagnostic approach for NBIA cases, from clinical features and brain imaging findings to the genetic etiology.

RESUMO A neurodegeneração com acúmulo cerebral de ferro (sigla em inglês NBIA) representa um grupo heterogêneo e complexo de doenças neurodegenerativas hereditárias, caracterizada pelo acúmulo cerebral de ferro, especialmente nos núcleos da base. O quadro clínico das NBIAs em geral inclui distúrbios do movimento, particularmente parkinsonismo e distonia, disfunção cognitiva, sinais piramidais e anormalidades da retina. As formas de NBIA descritas até o momento incluem neurodegeneração associada a pantothenase kinase (PKAN), neurodegeneração associada a phospholipase A2 (PLAN), neuroferritinopatia, aceruloplasminemia, neurodegeneração associada a beta-propeller protein (BPAN), síndrome de Kufor-Rakeb, neurodegeneração associada a mitochondrial membrane protein (MPAN), neurodegeneração associada a “fatty acid hydroxylase” (FAHN), neurodegeneração associada a coenzyme A synthase protein (CoPAN) e síndrome de Woodhouse-Sakati. Esta revisão é uma orientação para o diagnóstico das NBIAs, partindo das características clínicas e achados de neuroimagem, até a etiologia genética.

Eye of the tiger sign in neurodegeneration with brain iron accumulation: a case report.

Neurodegeneration with brain iron accumulation (NBIA) is a rare autosomal recessive disorder characterized by abnormal accumulation of ferritin in globus pallidus of brain. Magnetic resonance imaging (MRI) of brain demonstrates a characteristic ‘eye-of-the-tiger’ sign. We describe a case of NBIA in a child with classical clinical and MRI of brain features.

Pantothenate Kinase Associated Neurodegeneration: A Case Report.

Pantothenate kinase-associated neurodegeneration (PKAN) is a form of neurodegeneration with brain iron accumulation (NBIA), formerly called Hallervorden-Spatz syndrome. PKAN is the first described inborn error of coenzyme A metabolism. PKAN encompasses two clinical subtypes, classic and atypical. We here report an eight year girl diagnosed as classic PKAN. We also review the literature about PKAN.

A Novel PANK2 Mutation in a Patient with Atypical Pantothenate-Kinase-Associated Neurodegeneration Presenting with Adult-Onset Parkinsonism

BACKGROUND: Pantothenate-kinase-associated neurodegeneration (PKAN) is an autosomal recessive neurodegenerative disorder that is characterized by progressive extrapyramidal signs, visual loss, and cognitive impairment. PKAN is caused by mutations in the pantothenate kinase gene (PANK2), which is located on chromosome 20p13 and encodes pantothenate kinase, the key regulatory enzyme in coenzyme-A biosynthesis. CASE REPORT: In this report we describe a case of atypical PKAN with a novel PANK2 mutation, presenting with a 10-year history of postural tremor involving both hands. Upon neurological examination, the patient's face was masked and he spoke in a monotonous voice. The patient presented with mild bradykinesia and rigidity that involved all of the extremities. Horizontal saccadic eye movements were slow and fragmented. Brain MRI revealed a typical "eye-of-the-tiger" sign. A mutation analysis revealed three PANK2 mutations: two in exon 3 (Asp 378Gly and Leu385CysfsX13) and one in exon 4 (Arg440Pro). CONCLUSIONS: Parkinsonism is not an unusual presenting symptom in patients with atypical PKAN, and so it is important for physicians to consider PKAN in the differential diagnosis of patients presenting with young-onset parkinsonism.