BACKGROUND:Knee osteoarthritis is a common disease in middle-aged and elderly people.It is a kind of disease that seriously affects the quality of life of patients and even has the risk of disability.Therefore,the pathogenesis and treatment of knee osteoarthritis have become the focus of research.In Chinese medicine,knee osteoarthritis is often treated as"biness,"which is closely related to"biness"caused by blood stasis and blood vessels blocking collaterals in the theory of"blood stasis"in traditional Chinese medicine.Iron overload is a kind of pathological state caused by iron metabolism disorder,which highly coincides with the pathogenic characteristics and clinical manifestations of the"blood stasis"theory of traditional Chinese medicine,and is a risk factor that promotes the development of knee osteoarthritis. OBJECTIVE:Based on the"blood stasis"theory,to summarize the effects of iron overload on cartilage metabolism and subchondral bone reconstruction,to lay a new theoretical foundation for the treatment of knee osteoarthritis with traditional Chinese medicine,and to explore the therapeutic effect of traditional Chinese medicine for promoting blood circulation after interfering with bone tissue. METHODS:CNKI,WanFang database,PubMed and Web of Science databases were searched for relevant literature.The Chinese search terms were"ferroptosis,iron,iron overload,osteoarthritis,blood stasis"and the English search terms were"ferroptosis,iron,iron overload,osteoarthritis,TCM."In the end,76 articles were included for further review. RESULTS AND CONCLUSION:First of all,we explored the potential of the"blood stasis"theory in treating knee osteoarthritis,and found that"blood stasis"is a crucial part in the progress of knee osteoarthritis,indicating that the"blood stasis"theory is the key to the treatment of knee osteoarthritis in traditional Chinese medicine.Secondly,"blood stasis"and iron overload have a high degree of similarity in pathogenic factors,clinical manifestations,and pathogenic characteristics,suggesting the possibility of"blood stasis"theory in treating iron overload.This finding reminds us that iron overload may be an important mechanistic basis for the"blood stasis"theory in the treatment of knee osteoarthritis.The extracts of blood-activating drugs can relieve iron overload and treat knee osteoarthritis,but the specific mechanism is still unclear.Therefore,we believe that the relationship between"blood stasis"theory and iron overload and related mechanisms are important research directions for knee osteoarthritis in the future.The related mechanism of"blood stasis"theory to alleviate iron overload and then treat knee osteoarthritis also provides a theoretical basis for the modernization of traditional Chinese medicine,such as the development of new drugs and innovative usage,and has certain guiding significance for clinical practice.

ObjectiveTo study the effect of Guizhi Shaoyao Zhimutang （GSZMD） on cartilage destruction in mice with collagen-induced arthritis （CIA） and its mechanism. MethodThirty-six DBA/1 mice in SPF grades were randomly divided into 6 groups， namely， the normal group， the model group， the methotrexate （MTX） group， the low-dose GSZMD group， the medium-dose GSZMD group， and the high-dose GSZMD group. Except the normal group， mice in the other 5 groups were used to establish the model of CIA by secondary immunization. The mice were given normal saline， MTX （1.5 mg·kg^-1， 2 times a week）， and low， medium， and high-doses GSZMD （6.3， 12.6， 25.2 g·kg^-1·d^-1） by intragastric administration on the day of the onset of hind limb swelling for 4 weeks. The changes in the degree of foot swelling of mice in each group were observed and recorded. The content of matrix metalloproteinase （MMP）-1， MMP-3， MMP-9， and MMP-13 in serum was determined by enzyme-linked immunosorbent assay （ELISA）. The pathological changes in the ankle joint were observed by hematoxylin-eosin （HE） staining， and the cartilage destruction was observed by red fast green staining. The protein expression of the Janus kinase 2/signal transducer and activator of transcription 3 （JAK2/STAT3） signaling pathway in ankle joints were detected by Western blot. ResultAs compared with the normal group， the degree of foot swelling， the content of MMP-1， MMP-3， MMP-9， and MMP-13 in serum and the expression levels of phosphorylation （p）-JAK2/JAK2 and p-STAT3/STAT3 in ankle joints of the model group were increased （P<0.01）， and the joint damage was aggravated. As compared with the model group， the degrees of foot swelling of the mice in the MTX group and the low， medium， and high-dose GSZMD group were reduced （P<0.05， P<0.01）， and the content of MMP-1， MMP-3， MMP-9， and MMP-13 in serum was decreased （P<0.05， P<0.01）. The pathological joint damage was alleviated， and the expression levels of p-JAK2/JAK2 and p-STAT3/STAT3 in ankle joints were decreased in the MTX group and GSZMD groups （P<0.05， P<0.01）. ConclusionGSZMD can reduce the degree of joint swelling in mice with CIA， inhibit the expressions of MMP-1， MMP-3， MMP-9， and MMP-13， and alleviate the destruction of articular cartilage. Its mechanism is related to the JAK2/STAT3 signaling pathway.

Background and purpose:Leptomeningeal metastasis is a form of central nervous system metastasis of melanoma.High mobility group A2(HMGA2)has been proven to play an important role in the occurrence and development of various tumors,but its biological functions in leptomeningeal metastatic melanoma cells remain unclear.On the basis of building mouse models of central nervous system metastasis of melanoma,this study investigated the differences in cell migration and cell proliferation among leptomeningeal metastatic melanoma cells,primary site melanoma cells and brain parenchymal metastatic melanoma cells,and further clarified the effects of differentially expressed gene HMGA2 on cell migration and proliferation of leptomeningeal metastatic melanoma cells.Methods:B16 mouse melanoma cells(B16-parental cells,B16-Par)stably expressing tdTomato and luciferase were generated by lentiviral infection.Subsequently,B16 specific brain parenchymal metastatic cells(B16-brain metastatic cells,B16-BrM)and B16 specific leptomeningeal metastatic cells(B16-leptomeningeal metastatic cells,B16-LM)were collected after adaptive screening of metastatic sites in vivo.The differences in migration and proliferation among B16-Par,B16-BrM and B16-LM were assessed by wound healing assay and cell counting kit-8(CCK-8).RNA sequencing(RNA-seq)was used to analyze differential gene expression in B16-Par,B16-BrM and B16-LM,and HMGA2 gene specifically upregulated in B16-LM was screened out.The results were verified by real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR)and Western blot.Gene ontology(GO)analysis was performed for genes which were upregulated in B16-LM specifically.siRNA was used to interfere with the expression of HMGA2 gene in B16-LM,and the knock-down effect was verified by RTFQ-PCR and Western blot.The effects of knocking down HMGA2 on cell migration and proliferation were detected by wound healing assay and CCK-8 assay.Using GSE174401 data in Gene Expression Omnibus(GEO),the specificity of HMGA2 gene expression in leptomeningeal metastatic melanoma cells from patients was verified.Results:Compared with Par cells,tumor cells screened by the brain environment were more likely to colonize the central nervous system.B16-LM had stronger migration and proliferation abilities,and upregulated the expression of HMGA2 gene.GO analysis revealed that HMGA2 was associated with many biological processes such as angiogenesis and cell proliferation.When the expression of HMGA2 gene was knocked down,the migration and proliferation of B16-LM could be inhibited.HMGA2 was upregulated in leptomeningeal metastatic melanoma cells from patients.Conclusion:Leptomeningeal metastatic melanoma cells had relatively unique cellular characteristics,which promoted cell migration and proliferation by upregulating HMGA2 gene expression.