Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.

BACKGROUND:It has also been confirmed that ferroptosis is closely related to a variety of musculoskeletal diseases,such as rheumatoid arthritis,osteosarcoma,and osteoporosis.The pathophysiological mechanisms of ferroptosis and osteoporosis need to be further studied and elucidated to broaden our understanding of iron metabolism and osteoporosis.It will provide research ideas for the future elucidation of new mechanisms of osteoporosis and the development of new technologies and drugs for the treatment of osteoporosis. OBJECTIVE:To provide an overview of the current status of research on ferroptosis in osteoporosis,to provide a new direction for future research on the specific molecular mechanisms of osteoporosis,and to provide more effective and better options for osteoporosis treatment strategies. METHODS:The first author used the computer to search the literature published from 2000 to 2024 in CNKI,WanFang,VIP,and PubMed databases with search terms"ferroptosis,iron metabolism,osteoporosis,osteoblast,osteoclast,bone metabolism,signal pathway,musculoskeletal,review"in Chinese and English.A total of 68 articles were finally included according to the selection criteria. RESULTS AND CONCLUSION:(1)Ferroptosis is a new type of cell death discovered in recent years,which is usually accompanied by a large amount of iron accumulation and lipid peroxidation during cell death,and its occurrence is iron-dependent.This is distinctly different from several types of cell death that are currently being hotly studied(e.g.,cellular pyroptosis,necrotic apoptosis,cuproptosis,and autophagy).(2)Intracellular iron homeostasis is manifested as a balance between iron uptake,export,utilization,and storage.The body's iron regulatory system includes systemic and intracellular regulation.The main factor of systemic regulation is hepcidin produced by hepatic secretion,and cellular regulation depends on the iron regulatory protein/iron response element system.Of course,intracellular iron homeostasis can be controlled by other factors,such as hypoxia,cytokines,and hormones.(3)Lipid peroxidation causes oxidative damage to biological membranes(plasma membrane and internal organelle membranes),lipoproteins,and other lipid-containing molecules.Polyunsaturated fatty acid-containing phospholipids are important targets of lipid peroxidation.Free polyunsaturated fatty acid is an important substrate for lipid oxidation and can bind to the phospholipid bilayer,leading to over-oxidation and thus triggering lipid apoptosis.(4)Several studies have shown that osteoblasts are overloaded with iron in different ways,resulting in the accumulation of unstable ferrous iron and the generation of reactive oxygen species and lipid peroxides,causing ferroptosis of osteoblasts and ultimately a decrease in bone formation,affecting bone homeostasis and the development of osteoporosis.(5)Osteoclasts are large multinucleated cells formed by the fusion of mononuclear macrophage cell lines or bone marrow mesenchymal stem cells induced by nuclear factor-κB ligand receptor activator,and they have the function of bone resorption.Iron ions can promote osteoclast differentiation and bone resorption through the production of intracellular lipid reactive oxygen species,while iron chelators can inhibit osteoclast formation in vitro and thus affect the occurrence and development of osteoporosis.

BACKGROUND:Erythropoietin has anti-inflammatory,anti-apoptotic,and pro-bone defect repair effects.To date,fewer studies have been conducted on its effects and molecular mechanism underlying restorative dentin formation after pulp injury. OBJECTIVE:To explore the effect of erythropoietin on restorative dentin formation after pulp injury. METHODS:(1)Animal experiment:Thirty-two rats were randomly divided into control group(n=16)and experimental group(n=16).In the experimental group,collagen sponges containing erythropoietin were used to directly cap the pulp at the pulp injury,and in the control group,collagen sponges containing PBS were used to directly cap the pulp at the exposed pulp injury.The cavity was then closed with glass ionomer adhesive.After 2 and 4 weeks of treatment,the maxillary bones of the two groups were collected,and the expression of nestin in dentin was detected by immunohistochemistry,and the reparative dentin production was observed by hematoxylin-eosin staining.The maxillae of four Sprague-Dawley rats were taken for immunohistochemical detection of erythropoietin expression in molar and incisor teeth.(2)Cell experiment:Human dental pulp cells,human periodontal ligament cells and human gingival fibroblasts were obtained from human dental tissue,periodontal ligament,and gingival tissue.Real-time reverse transcription PCR(RT-PCR)was used to detect the mRNA expression of erythropoietin.Erythropoietin,dentin sialophosphoprotein,dentin matrix protein 1,and nestin mRNA levels in human pulp cells were detected by RT-PCR under induced or uninduced odontoblastic differentiation.After down-regulation of erythropoietin expression or exogenous administration of erythropoietin intervention under induced or uninduced differentiation odontoblastic differentiation,the relative mRNA expression of dentin sialophosphoprotein and dentin matrix protein 1 in human pulp cells was detected by RT-PCR,and the formation of mineralized nodules was detected by alizarin red S staining,and mRNA and protein expressions of bone morphogenetic protein 2 were detected by RT-PCR and western blot,respectively. RESULTS AND CONCLUSION:(1)Animal experiment:Compared with the control group,the restorative dentin production and nestin expression were higher in the experimental group after 2 and 4 weeks of treatment.The expression of erythropoietin was weakly positive in pulp,odontoblastic cell layer and periodontal membrane of the rat's first maxillary molar,and strongly positive in odontoblasts.(2)Cell experiment:The mRNA expression of erythropoietin was higher in human dental pulp cells than in the other two types of cells.The mRNA expressions of dentin sialophosphorin,dentin matrix protein 1,nestin,erythropoietin and bone morphogenetic protein 2 in human pulp cells increased and the formation of mineralized nodules during odontoblastic differentiation under induction compared with non-induction conditions.The mRNA expression of dentin sialophosphoprotein,dentin matrix protein 1,nestin,bone morphogenetic protein 2 and the formation of mineralized nodules were decreased in human pulp cells after downregulation of erythropoietin under induced odontoblastic differentiation,and the protein expression of bone morphogenetic protein 2 was also decreased.After exogenous erythropoietin intervention,the expression of the above indexes in human dental pulp cells increased.To conclude,erythropoietin can promote the formation of dentin to some extent.

POEMS syndrome is a rare condition associated with plasma cell disorders， and it often involves multiple systems and has diverse clinical manifestations. This article reports two cases of POEMS syndrome with hepatosplenomegaly as the initial manifestation. During the course of the disease， the patients presented with lower limb weakness， hepatosplenomegaly， lymph node enlargement， ascites， hypothyroidism， positive M protein， and skin hyperpigmentation， and ¹⁸F-FDG PET-CT imaging revealed bone lesions mainly characterized by osteolytic changes and plasma cell tumors. There was an increase in the serum level of vascular endothelial growth factor. The patients were finally diagnosed with POEMS syndrome， and the symptoms were relieved after immunomodulatory treatment.

In recent years, the incidence of dry eye disease(DED)is increasing, positioning it as one of the most prevalent diseases affecting the ocular surface. Inflammatory response is the pathological basis of DED, involving various inflammatory mediators and inflammatory signaling pathways. Consequently, anti-inflammatory treatment emerges as a fundamental strategy for preventing and managing DED. This review summarizes the classic inflammatory factors involved in the development and progression of DED, including interleukins, tumor necrosis factor, matrix metalloproteinases, chemokines, and cell adhesion molecules. It also discusses the relevant inflammatory signaling pathways: the MAPKs pathway, NF-κB pathway, Wnt pathway and TLR pathway. Additionally, this review addresses the mechanisms of action and alterations in relevant biomarkers associated with current first-line recommended anti-inflammatory therapies, including corticosteroids, immunosuppressants, nonsteroidal anti-inflammatory drugs, and traditional Chinese medicine approaches to inflammation management. This comprehensive overview aims to enhance understanding of the inflammatory mechanisms underlying DED while exploring future therapeutic prospects.

In recent years, the incidence of dry eye disease(DED)is increasing, positioning it as one of the most prevalent diseases affecting the ocular surface. Inflammatory response is the pathological basis of DED, involving various inflammatory mediators and inflammatory signaling pathways. Consequently, anti-inflammatory treatment emerges as a fundamental strategy for preventing and managing DED. This review summarizes the classic inflammatory factors involved in the development and progression of DED, including interleukins, tumor necrosis factor, matrix metalloproteinases, chemokines, and cell adhesion molecules. It also discusses the relevant inflammatory signaling pathways: the MAPKs pathway, NF-κB pathway, Wnt pathway and TLR pathway. Additionally, this review addresses the mechanisms of action and alterations in relevant biomarkers associated with current first-line recommended anti-inflammatory therapies, including corticosteroids, immunosuppressants, nonsteroidal anti-inflammatory drugs, and traditional Chinese medicine approaches to inflammation management. This comprehensive overview aims to enhance understanding of the inflammatory mechanisms underlying DED while exploring future therapeutic prospects.

The purpose of this paper is to explore the decoction and dosing methods of rhubarb root and rhizome in classical prescriptions and to provide a reference basis for the clinical use of rhubarb root and rhizome. By collating the relevant classical prescriptions of rhubarb root and rhizome in Shanghan Lun and Jingui Yaolüe, the relationship between its decoction and dosing methods and the syndrome was analyzed. The decoction of rhubarb root and rhizome in classical prescriptions can be divided into three categories: simultaneous decoction, decoction later, and other methods (impregnation in Mafei decoction, decoction with water from the well spring first taken in the morning, and pills). If it enters the blood level or wants to slow down, rhubarb root and rhizome should be decocted at the same time with other drugs. If it enters the qi level and wants to speed up, rhubarb root and rhizome should be decocted later. If it wants to upwardly move, rhubarb root and rhizome should be immersed in Mafei decoction. If it wants to suppress liver yang, rhubarb root and rhizome should be decocted with water from the well spring first taken in the morning. If the disease is prolonged, rhubarb root and rhizome should be taken in pill form. The dosing methods of rhubarb root and rhizome can be divided into five categories: draught, twice, three times, before meals, and unspecified. For acute and serious illnesses with excess of pathogenic qi and adequate vital qi, we choose draught. For gastrointestinal diseases, we choose to take the medicine twice. For achieving a moderate and long-lasting effect, we choose to take the medicine three times. If the disease is located in the lower part of the heart and abdomen, we choose to take it before meals. The use of rhubarb root and rhizome in clinical practice requires the selection of the appropriate decoction and dosing methods according to the location of the disease, the severity of the disease, the patient′s constitution, and the condition after taking the medicine.

Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.