BACKGROUND:Prolyl hydroxylase domain 2(PHD2)inhibitors can regulate bone metabolism and relieve osteoporosis in ovariectomized rats.cpd17 is a small molecule oral PHD2 inhibitor newly developed by China Pharmaceutical University.It is effective in the treatment of renal anemia with few side effects,but its effect on bone formation and bone resorption is still unclear. OBJECTIVE:To investigate the effects of cpd17 on mouse osteogenic precursor cells. METHODS:Osteogenic precursor cells were treated with cpd17.Alkaline phosphatase activity and extracellular matrix mineralization were measured,and the expression levels of osteogenesis-and osteoclastogenesis-related markers,as well as PHD2 and hypoxia-inducible factor 1α,were detected.After inhibition of the hypoxia-inducible factor 1α pathway using LW6(a hypoxia-inducible factor 1α pathway inhibitor),alkaline phosphatase activity and extracellular matrix mineralization were detected again,as well as the expression levels of osteogenesis-and osteoclastogenesis-related markers,PHD2 and hypoxia-inducible factor 1α. RESULTS AND CONCLUSION:cpd17 significantly enhanced alkaline phosphatase activity and extracellular matrix mineralization,up-regulated the expression of osteogenesis-related markers,down-regulated the expression of osteoclastogenesis-related markers,up-regulated the expression of hypoxia-inducible factor 1α,down-regulate the expression of PHD2.However,cpd17's effects were significantly attenuated by LW6.To conclude,the PHD2 inhibitor cpd17 promotes osteogenic differentiation and inhibits osteoclastic differentiation through activation of the hypoxia-inducible factor 1α signaling pathway.

BACKGROUND:Needle-knife release of the ligamentum flavum can effectively improve symptoms in patients with lumbar degeneration,and ultrasound guidance can increase the precision of needle-knife release;however,the specific effects of needle-knife release of the ligamentum flavum on the degenerated intervertebral discs and the possible mechanisms remain to be clarified. OBJECTIVE:To investigate the effect of ultrasound-guided needle-knife release of the ligamentum flavum. METHODS:Twenty-four New Zealand rabbits were randomized into control(n=6)and model(n=18)groups.A rabbit model of lumbar disc degeneration model was established in the model group by cutting the supraspinous and interspinous ligaments of the L5/6 and L6/7 segments to maintain a standing posture and apply axial load to the lumbar spine.After successful modeling,the model rabbits were subdivided into a control group,a model group,an ultrasonic needle-knife group,and a sham needle-knife group according to a random number table method,with six animals in each group.The ultrasonic needle-knife group underwent ultrasound-guided needle-knife release of the right yellow ligament of L7/S1,once every week,for a total of four times.The needle-knife approach in the sham needle-knife group was the same as that in the ultrasound needle-knife group,but the ligamentum flavum was not released.At 30 days after the intervention,MRI was used to observe the changes in the signal intensity of the nucleus pulposus within the L7/S1 segment.Hematoxylin-eosin staining was used to observe the morphological changes of the L7/S1 segment.Immunohistochemical staining was used to detect the expression of type I and II collagen in the nucleus pulposus of the L7/S1 segment.RT-PCR and western blot were used to detect the expression of integrin α5 and β1,p38,and nuclear factor κB in the L7/S1 segment. RESULTS AND CONCLUSION:MRI findings indicated that the nucleus pulposus of the intervertebral disc of rabbits in the model group was gray-black in color,and the gray value of the nucleus pulposus was significantly lower than that of the control group(P<0.01).The brightness of the nucleus pulposus of the intervertebral disc of the rabbits in the ultrasonic needle-knife group was elevated compared with that of the model group,and the gray value of the nucleus pulposus was higher than that of the model group(P<0.01).Results from hematoxylin-eosin staining showed that in the model group,the shape of the nucleus pulposus was irregular,the number of nucleus pulposus cells was reduced,the extracellular matrix was compressed,the fibrous ring was ruptured,the structure and boundary of the end plate were unclear,and the chondrocytes were arranged disorderly.Compared with the model group,the ultrasonic needle-knife group showed an increase in the number of the nucleus pulposus,an improvement in the rupture of the fibrous ring,and more regular arrangement of cartilage endplate cells.Results from immunohistochemical staining showed an increase in positive expression of type I collagen(P<0.01)and a decrease in positive expression of type II collagen in the nucleus pulposus of the model group compared with the control group as well as a decrease in positive expression of type I collagen and an increase in positive expression of type II collagen in the nucleus pulposus of the ultrasonic needle-knife group compared with the model group(P<0.01).RT-PCR and western blot assays showed that the mRNA and protein expression of integrin α5,integrin β1,p38,and nuclear factor κB in the intervertebral discs of rabbits in the model group were increased compared with that in the control group(P<0.01);the mRNA and protein expression of integrin α5,integrin β1,p38,and nuclear factor κB in the intervertebral discs of rabbits in the ultrasonic needle-knife group was decreased compared with that in the model group(P<0.01).To conclude,ultrasound-guided needle-knife release of the ligamentum flavum can improve the degree of lumbar disc degeneration in rabbits,which may be related to the inhibition of p38 and nuclear factor-κB expression by modulating integrin α5 and β1 expression.

BACKGROUND:As the end bearing joint of the human body,the ankle joint bears the top-down pressure of the body,which leads to the ankle joint is easy to be damaged in the movement,can induce functional ankle instability,which negatively affects daily life.The study of lower extremity biomechanics in patients with functional ankle instability during counter movement jump is of great significance for scientific training,prevention of ankle injury,and clinical rehabilitation after injury. OBJECTIVE:To investigate the kinetics and kinematics of lower limbs in the longitudinal jumping of functional ankle instability population. METHODS:From March to September 2023,15 male patients with functional ankle instability and 15 healthy people,aged 22-28 years old,were recruited in Soochow University.All subjects completed counter movement jump experiment.Vicon infrared high-speed motion capture system and Kistler three-dimensional force measuring table were used to simultaneously collect the lower limb kinematics and kinetics indexes of the two groups of subjects at the take-off stage of counter movement jump,the instant off the ground,the initial landing moment and the peak moment of vertical ground reaction force. RESULTS AND CONCLUSION:(1)At the instant off the ground,the affected side of the functional ankle instability group showed smaller knee internal rotation moment(P=0.020)and smaller ankle internal rotation moment(P=0.009)compared with the affected side of the healthy control group.(2)At the moment of landing,the affected side of the functional ankle instability group showed a smaller hip flexion angle than the affected side of the healthy control group(P=0.039).Compared with the healthy control group,functional ankle instability group showed smaller hip abduction angle(P=0.022),smaller knee varus angle(P=0.010),larger knee external rotation angle(P=0.021),smaller ankle varus angle(P=0.004),and smaller external ankle rotation angle(P=0.008).(3)At the peak of vertical ground reaction force,functional ankle instability group showed a smaller ankle varus angle than healthy control group(P=0.044).(4)The results showed that the lower limb biomechanical characteristics of the patients with functional ankle instability were abnormal compared with the healthy people during counter movement jump,which mainly showed the changes of the kinematics and kinetics indexes of the lower limb joints in the sagittal plane and the frontal plane at the moment of lift-off and landing.These changes reflect that people with functional ankle instability adopt rigid take-off and landing patterns when performing counter movement jump,tend to transfer the load of the affected ankle joint to other joints of the lower limb,and show compensatory phenomenon of the healthy lower limb.Therefore,detection and correction of abnormal biomechanical features should be a part of rehabilitation training for those with functional ankle instability.

BACKGROUND:How to effectively promote bone regeneration and bone reconstruction after bone injury has always been a key issue in clinical bone repair research.The use of biological and degradable materials loaded with bioactive factors to treat bone defects has excellent application prospects in bone repair. OBJECTIVE:To investigate the effect of polylactic acid-glycolic acid copolymer(PLGA)composite scaffold modified by lysine-grafted graphene oxide nanoparticles(LGA-g-GO)on osteogenic differentiation and new bone formation. METHODS:PLGA was dissolved in dichloromethane and PLGA scaffold was prepared by solvent evaporation method.PLGA/GO composite scaffolds were prepared by dispersing graphene oxide uniformly in PLGA solution.LGA-g-GO nanoparticles were prepared by chemical grafting method,and the PLGA/LGA-g-GO composite scaffolds were constructed by blending LGA-g-GO nanoparticles at different mass ratios(1%,2%,and 3%)with PLGA.The micromorphology,hydrophilicity,and protein adsorption capacity of scaffolds of five groups were characterized.MC3T3 cells were inoculated on the surface of scaffolds of five groups to detect cell proliferation and osteogenic differentiation. RESULTS AND CONCLUSION:(1)The surface of PLGA scaffolds was smooth and flat under scanning electron microscope,while the surface of the other four scaffolds was rough.The surface roughness of the composite scaffolds increased with the increase of the addition of LGA-g-GO nanoparticles.The water contact angle of PLGA/LGA-g-GO(3%)composite scaffolds was lower than that of the other four groups(P<0.05).The protein adsorption capacity of PLGA/LGA-g-GO(1%,2%,and 3%)composite scaffolds was stronger than PLGA and PLGA/GO scaffolds(P<0.05).(2)CCK-8 assay showed that PLGA/LGA-g-GO(2%,3%)composite scaffold could promote the proliferation of MC3T3 cells.Alkaline phosphatase staining and alizarin red staining showed that the cell alkaline phosphatase activity in PLGA/LGA-g-GO(2%,3%)group was higher than that in the other three groups(P<0.05).The calcium deposition in the PLGA/GO and PLGA/LGA-g-GO(1%,2%,and 3%)groups was higher than that in the PLGA group(P<0.05).(3)In summary,PLGA/LGA-g-GO composite scaffold can promote the proliferation and osteogenic differentiation of osteoblasts,and is conducive to bone regeneration and bone reconstruction after bone injury.

BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

BACKGROUND:Troxerutin has been found to have a significant ameliorative effect on brain disorders,but there are fewer studies on the effects of troxerutin on the treatment of cerebral infarction and on neuronal cells. OBJECTIVE:To investigate the mechanism by which troxerutin regulates nuclear factor-κB signaling pathway to reduce brain injury and neuronal apoptosis in cerebral infarction rats. METHODS:Fifty clean grade rats were randomized into healthy group,model group,and troxerutin+nuclear factor-κB agonist group,troxerutin group,and nuclear factor-κB inhibitor group.Except for the healthy group,all other groups were used to establish a rat model of cerebral infarction by arterial ligation.The healthy and model groups were treated once a day with an equal amount of physiological saline by gavage.The troxerutin+nuclear factor-κB agonist group was intervened with 72 mg/kg troxerutin by gavage+20 mg/kg RANK intraperitoneally.The troxerutin group was treated with 72 mg/kg troxerutin by gavage.The nuclear factor κB inhibitor group was intervened intraperitoneally with 120 mg/kg nuclear factor κB inhibitor pyrrolidine disulfiram.Administration in each group was given once a day for 30 continuous days.Zea-longa was used to detect neurological damage in rats,hematoxylin-eosin staining was used to observe pathological changes,TUNEL was used to detect neuronal apoptosis,and immunoblotting and PCR were used to detect the expression of nuclear factor-κB p65 and nuclear factor-κB p50 at protein and mRNA levels,respectively. RESULTS AND CONCLUSION:Compared with the healthy group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65,nuclear factor-κB p50 mRNA and protein expression levels were elevated in the model group(P＜0.05).Compared with the model group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were decreased in the troxerutin+nuclear factor-κB agonist group(P＜0.05).Compared with the troxerutin+nuclear factor-κB agonist group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were reduced in the troxerutin group and nuclear factor-κB inhibitor group(P＜0.05).In addition,there was no difference between the troxerutin group and the nuclear factor-κB inhibitor group(P＞0.05).In the model group,there was a large number of cytoplasmic vacuolation,obvious edema and necrosis,and a large number of inflammatory cell infiltrations.In the troxerutin+nuclear factor-κB agonist,the swelling of brain tissue was reduced,and reticulate structures and condensed cells were reduced,still with some edema.In the troxerutin group and nuclear factor-κB inhibitor group,brain tissue swelling,neuronal edema degeneration,cytoplasmic vacuolation and neuronal nucleus consolidation were reduced,and the inflammatory cell infiltration was significantly decreased.To conclude,troxrutin can reduce the expression of neurological impairment,inhibit neuronal apoptosis and improve the pathological injury of brain tissue in rats with cerebral infarction,and its mechanism of action may be related to the modulation of nuclear factor-κB expression and related signaling pathways.

BACKGROUND:Osteosarcoma has a complex pathogenesis and a poor prognosis.While advancements in medical technology have led to some improvements in the 5-year survival rate,substantial progress in its treatment has not yet been achieved. OBJECTIVE:To screen key molecular markers in osteosarcoma,analyze their relationship with osteosarcoma treatment drugs,and explore the potential disease mechanisms of osteosarcoma at the molecular level. METHODS:GSE99671 and GSE284259(miRNA)datasets were obtained from the Gene Expression Omnibus database.Differential gene expression analysis and Weighted Gene Co-expression Network Analysis(WGCNA)on GSE99671 were performed.Functional enrichment analysis was conducted using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes separately for the differentially expressed genes and the module genes with the highest positive correlation to the disease.The intersection of these module genes and differentially expressed genes was taken as key genes.A Protein-Protein Interaction network was constructed,and correlation analysis on the key genes was performed using CytoScape software,and hub genes were identified.Hub genes were externally validated using the GSE28425 dataset and text validation was conducted.The drug sensitivity of hub genes was analyzed using the CellMiner database,with a threshold of absolute value of correlation coefficient|R|>0.3 and P<0.05. RESULTS AND CONCLUSION:(1)Differential gene expression analysis identified 529 differentially expressed genes,comprising 177 upregulated and 352 downregulated genes.WGCNA analysis yielded a total of 592 genes with the highest correlation to osteosarcoma.(2)Gene Ontology enrichment results indicated that the development of osteosarcoma may be associated with extracellular matrix,bone cell differentiation and development,human immune regulation,and collagen synthesis and degradation.Kyoto Encyclopedia of Genes and Genomes enrichment results showed the involvement of pathways such as PI3K-Akt signaling pathway,focal adhesion signaling pathway,and immune response in the onset of osteosarcoma.(3)The intersection analysis revealed a total of 59 key genes.Through Protein-Protein Interaction network analysis,8 hub genes were selected,which were LUM,PLOD1,PLOD2,MMP14,COL11A1,THBS2,LEPRE1,and TGFB1,all of which were upregulated.(4)External validation revealed significantly downregulated miRNAs that regulate the hub genes,with hsa-miR-144-3p and hsa-miR-150-5p showing the most significant downregulation.Text validation results demonstrated that the expression of hub genes was consistent with previous research.(5)Drug sensitivity analysis indicated a negative correlation between the activity of methotrexate,6-mercaptopurine,and pazopanib with the mRNA expression of PLOD1,PLOD2,and MMP14.Moreover,zoledronic acid and lapatinib showed a positive correlation with the mRNA expression of PLOD1,LUM,MMP14,PLOD2,and TGFB1.This suggests that zoledronic acid and lapatinib may be potential therapeutic drugs for osteosarcoma,but further validation is required through additional basic experiments and clinical studies.

BACKGROUND:In recent years,with the rapid development of biomedicine,the study of brain aging and exosomes has attracted more and more attention,but there is no bibliometrics analysis in this field. OBJECTIVE:To objectively analyze domestic and foreign literature on brain aging and exosomes in the past 15 years,to summarize the research status,hot spots,and development trends in this field. METHODS:Using the core database of Web of Science as a search platform,we downloaded the literature on brain aging and exosomes published from the establishment of the database to December 28,2022,and analyzed the data from the aspects of country or region,institution,author,keywords,and co-cited literature using CiteSpace 6.1.R6 visualization software. RESULTS AND CONCLUSION:A total of 1 045 research articles were included,and the number of publications on brain aging and exosomes research both domestically and internationally was showing an increasing trend year by year.The United States ranked first with 429 papers,and China ranked second with 277 papers.Louisiana State University ranked first with 16 articles.Professor Lukiw Walter J from Louisiana State University in the United States was the author with the highest number of publications,and Professor Bartel DP from the Massachusetts Institute of Technology was the author with the most citations.The most prolific Journal was the International Journal of Molecular Sciences.Alzheimer's disease,microRNA,gene expression,extracellular vesicles,exosomes,oxidative stress,and biomarkers are the most relevant terms.According to the research on hot topics,biomarkers have become a new research hotspot.The above results indicate that the research on brain aging and exosomes has gradually increased in the past 15 years.The research direction has gradually shifted from the initial exploration of the expression of miRNAs in central nervous system diseases related to brain aging to the search for biomarkers that can identify and diagnose neurodegenerative diseases.The study of exocrine miRNAs to protect central nervous system from damage has emerged as promising therapeutic strategy.

BACKGROUND:A large number of studies have confirmed that the therapeutic effectiveness of mesenchymal stem cell secretome is comparable to that of mesenchymal stem cells,but the mechanism of its action is still unclear. OBJECTIVE:To summarize the research progress of mesenchymal stem cell secretome in recent years,to investigate the molecular mechanism of its therapeutic effect,to analyze the current problems and to look forward to the future development. METHODS:The terms"exosomes,mesenchymal stem cells secrete,extracellular vesicles,mesenchymal stem cells,mechanism"were used as English search terms in the PubMed database.Articles that were not related to the research purpose of the article and duplicated articles were excluded.At the same time,we combined the method of literature tracking.Finally,109 articles that met the criteria were incuded for the review. RESULTS AND CONCLUSION:(1)The mesenchymal stem cell secretome promotes tissue repair and regeneration through delivering genetic material,immunomodulatory factors,growth factors,etc.to target cells,by activating anti-apoptotic,regulating angiogenesis,modulating fibrosis and pro-survival pathways in target cells.(2)The potential of mesenchymal stem cell secretome in disease therapy has also been confirmed.Numerous research results have shown that mesenchymal stem cell secretome can be used as a new cell-free treatment for inflammatory and degenerative diseases.(3)Mesenchymal stem cell secretome has been engineered to have more efficient therapeutic effects in recent years.However,due to the heterogeneity of the mesenchymal stem cell secretome and the complexity of its components,the exact mechanism of its therapeutic effect is still unclear.(4)At present,further research is needed to identify the key targets of mesenchymal stem cell secretome,and innovative specific and enhanced mesenchymal stem cell secretome should be developed by combining with engineering and genetic engineering technologies in the future.

BACKGROUND:The decreased postural control ability due to mild cognitive impairment in elderly people leads to the increased risk of falls.Dual-task is the primary research paradigm for evaluating the relationship between cognition and postural control in the scenes close to real life.The sample entropy of the plantar center of pressure(COP)displacement during standing can represent the complexity of postural control. OBJECTIVE:Based on the COP displacement sample entropy,to analyze the differences in postural stability characteristics and control strategies between older adults with mild cognitive impairment and cognitively normal older adults during the dual-task with postural control and spatial working memory,aiming to explore the impact of cognitive impairment on the postural control ability during standing. METHODS:Sixteen older adults with mild cognitive impairment and 17 cognitively normal older adults were eligible and selected for the study.They completed five test tasks,including spatial working memory,double-feet balance stance,Romberg stance,double-feet balance stance-spatial working memory dual-task,and Romberg stance-spatial working memory dual-task,with three valid completions of each task.The plantar COP data were collected by the Kistler 3D force platform.The indicators included cognitive behavior(cognitive score and reaction time)and kinematic indexes(COP displacement and sample entropy). RESULTS AND CONCLUSION:The older adults with mild cognitive impairment performed the spatial working memory task with the greatest cognitive score and the shortest reaction time,the double-feet balance stance-spatial working memory dual-task with moderate cognitive score and reaction time,and the Romberg stance-spatial working memory dual-task with the smallest cognitive score and the longest reaction time,where the differences were significant among the tasks(P<0.05).In the older adults with mild cognitive impairment,the anterior-posterior and medial-lateral COP displacements were significantly greater,and their sample entropy values were significantly smaller in the double-feet balance stance-spatial working memory dual-task and Romberg stance-spatial working memory dual-task than in the double-feet balance stance and Romberg stance tasks(P<0.05).In the spatial working memory task,there were no significant differences in cognitive score and reaction time between the both groups(P>0.05);however,in the double-feet balance stance-spatial working memory dual-task and Romberg stance-spatial working memory dual-task,cognitive scores were significantly smaller and reaction times were longer in the older adults with mild cognitive impairment compared with the cognitively normal older adults(P<0.05).In the double-feet balance stance-spatial working memory dual-task and Romberg stance-spatial working memory dual-task,the older adults with mild cognitive impairment exhibited significantly greater anterior-posterior and medial-lateral COP displacements and significantly smaller sample entropy values compared with the cognitively normal older adults(P<0.05).All findings indicate that compared with cognitively normal older adults,older adults with mild cognitive impairment exhibit smaller complexity,poorer systematic adaption and decreased automatic regulation of the postural control during performing the dual-tasks,who are more susceptible to spatial working memory interference,leading to the increased risk of falls.