BACKGROUND:Iron overload is an independent factor inducing osteoporosis,but the action mechanism is currently unclear.Therefore,exploring the effects of iron overload on osteoblast-related cells will help to deeply understand the pathogenesis of osteoporosis and provide potential strategies for osteoporosis treatment.OBJECTIVE:To explore the effects of iron overload environment on osteoblast precursor cell activity,ferroptosis,and osteogenic differentiation.METHODS:Osteoblast precursor cells(MC3T3-E1 cells)were divided into blank group,iron overload group,fer-1 group,and deferoxamine group.The iron overload group was treated with 300 μmol/L ammonium ferric citrate in the culture medium for 48 hours to simulate the iron overload microenvironment.The cells in fer-1 group and deferoxamine group were pretreated with 5 μmol/L antioxidant fer-1 and 5 μmol/L deferoxamine for 8 hours,respectively,and then added with 300 μmol/L ammonium ferric citrate for 48 hours.CCK-8 assay was used to determine the cell viability.Intracellular reactive oxygen species levels were detected employing a reactive oxygen species fluorescent probe.Changes in mitochondrial membrane potential were monitored with a mitochondrial membrane potential fluorescent probe.Mitochondrial morphology was observed employing transmission electron microscopy.Cellular glutathione levels were measured with a reduced glutathione colorimetric assay kit.Lipid peroxidation levels were assessed with a malondialdehyde colorimetric assay kit.Cellular ferrous ion levels were determined with a ferrous ion colorimetric assay kit.The osteogenic and mineralization capabilities of the cells were verified by alkaline phosphatase staining and alizarin red staining.Collagen secretion ability was detected using Sirius Red staining.The expression of osteogenic/ferroptosis-related genes and proteins was examined through reverse transcription quantitative polymerase chain reaction and western blot analysis.RESULTS AND CONCLUSION:(1)In an iron-overload environment,the mitochondrial membrane potential of cells decreased and their structure was compromised,with an elevation in intracellular lipid peroxidation levels and a downregulation of genes and proteins associated with ferroptosis resistance.However,pretreatment with fer-1 and deferoxamine led to an increase in mitochondrial membrane potential and partial restoration of morphology,a reduction in intracellular lipid peroxidation levels,and an upregulation of genes and proteins related to ferroptosis resistance.(2)In an iron-overload environment,the levels of cellular alkaline phosphatase,the formation of mineralized nodules,and the synthesis of collagen fibers were all found to be decreased.Pretreatment with fer-1 and deferoxamine was observed to upregulate the expression of osteogenic differentiation in cells.(3)In summary,iron overload could increase intracellular oxidative stress levels,mediate ferroptosis in MC3T3-E1 cells and inhibit osteogenic differentiation,thereby inducing osteoporosis.Therefore,maintaining iron homeostasis and inhibiting osteogenesis-related ferroptosis may be potential strategies to prevent or treat osteoporosis.

Objective:To explore the role and molecular mechanisms of S100A6 protein in neonatal meningitis caused by Streptococcus agalactiae. Methods:Human brain microvascular endothelial cells (HBMECs) were used as an in vitro experimental model, and siRNA was employed to construct S100A6 gene knockdown HBMECs strain. The S100A6 gene overexpression cell line was established by lentiviral transfection method. Western blot was used to detect the expression level of S100A6 protein in HBMECs after Streptococcus agalactiae infection, and the change in intracellular inflammatory cytokine protein levels after S100A6 gene knockdown or overexpression. A neonatal bacterial meningitis model was established by injecting Streptococcus agalactiae suspension into the cisterna magna of neonatal Sprague-Dawley (SD) rats. HE staining was used to observe pathological changes in brain tissue; immunohistochemistry was used to detect the expression and distribution of S100A6 protein in brain tissue; Western blot and ELISA were used to measure S100A6 protein levels in cerebrospinal fluid (CSF). Results:Compared with the control group, the intracellular S100A6 protein level in HBMECs increased significantly following Streptococcus cgalactiae infection. After S100A6 gene knockdown, the invasion rate of Streptococcus agalactiae into the HBMECs was significantly reduced ( P<0.01), while intracellular TNF-α and IL-6 protein levels were elevated markedly ( P<0.01). In contrast, overexpression of S100A6 gene increased the invasion rate ( P<0.01) and notably decreased TNF-α and IL-6 protein levels ( P<0.001). In the neonatal SD rat bacterial meningitis model, HE staining revealed substantial neutrophil infiltration in brain tissue after Streptococcus agalactiae infection. Immunohistochemistry showed extensive deposition of S100A6 protein around the meninges, and significant expression of S100A6 protein was also detected in CSF. Conclusions:S100A6 protein is crucial in mediating neonatal meningitis caused by Streptococcus agalactiae infection. S100A6 gene knockdown promotes the production of intracellular inflammatory cytokines and reduces Streptococcus agalactiae invasion into cells, thereby alleviating bacteria-induced cellular damage. Additionally, the increased expression of S100A6 protein in brain tissue and CSF after Streptococcus agalactiae infection suggests its potential as a diagnostic biomarker for bacterial meningitis.

BACKGROUND:Titanium implants are widely used in clinical practice because of their high strength and good biocompatibility.However,during implantation,bacterial infection and tissue damage environment produce a large number of reactive oxygen species,which can easily lead to delayed tissue healing and surgical failure.Consequently,the development of titanium implants with antimicrobial and antioxidant properties becomes paramount. OBJECTIVE:Considering the potent antimicrobial attributes of copper ions and the remarkable antioxidant qualities of polyphenols,we proposed the fabrication of polyphenol-mediated copper ion coatings on titanium surfaces.These coatings were subsequently assessed for their in vitro antimicrobial and antioxidant properties. METHODS:Nanostructures were generated on the titanium surface using the alkali thermal method.The titanium was immersed in a solution containing tannic acid and copper ions to achieve polyphenol-mediated copper ion coatings.The surface morphology and water contact angle were detected.The loading and release of copper ions were examined using atomic absorption spectroscopy.Staphylococcus aureus was inoculated on the surface of pure titanium sheet(blank group),alkali heat treated titanium sheet(control group),and polyphenol mediated copper ion modified titanium sheet(experimental group)to observe the bacterial survival status.Osteoblast precursor cells MC3T3-E1 were co-cultivated on the surface of three groups of titanium sheets to assess their antioxidant properties and bioactivity. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the polyphenol-mediated copper ion modified titanium sheet had rod-like nanostructures and no cracks on the surface.The surface hydrophilicity of copper ion modified titanium sheet mediated by polyphenol was close to that of pure titanium sheet.Atomic absorption spectrometry results showed a 51%increase in the loading capacity of copper ions after polyphenol mediation,with a uniform release of copper ions.(2)The antibacterial rates of titanium sheets in the blank group,control group,and experimental group were 0%,21.65%,and 93.75%,respectively.The live/dead staining and CTC staining showed that the live bacteria on the surface of titanium plates in the blank group were the most,and the live bacteria on the surface of titanium plates in the experimental group were the least.(3)The results of live/dead staining and CCK-8 assay showed that the three groups of titanium sheets had good cytocompatibility,and the titanium sheets in the experimental group were more conducive to the proliferation of MC3T3-E1 cells.Active oxygen fluorescence probe detection exhibited that compared with the other two groups,the fluorescence intensity of active oxygen on the surface of the experimental group was significantly reduced.The results of alkaline phosphatase and alizarin red S staining showed that the osteogenic differentiation and extracellular matrix mineralization of MC3T3-E1 cells on the surface of titanium sheets in the experimental group were stronger than those in the other two groups.(4)These results show that the polyphenol-mediated copper ion coating has strong antibacterial and antioxidant properties and promotes osteogenic differentiation.

ObjectiveTo investigate the modifiable areal unit problem （MAUP） in the spatial pattern of Pseudostellaria heterophylla production regions and reveal the impact of statistical scales on the spatial distribution characteristics of this medicinal plant species. MethodsUsing multi-source data （literature records， field surveys， and statistical data）， we systematically analyzed the spatial patterns across three administrative levels （provincial， prefectural， and county scales）. Spatial autocorrelation （Moran's I） analysis， high-low clustering （Getis-Ord General G）， and hot/cold spot analysis （Getis-Ord Gi*） were employed. ResultsThe literature-based analysis showed that the production regions of P. heterophylla presented random distribution on the provincial scale and significant aggregation on the prefectural scale. The field survey data showed that the production regions displayed random distribution on the provincial scale but significant aggregation on both prefectural and county scales. The statistical data revealed that the production regions lacked spatial autocorrelation on the provincial scale but demonstrated significant aggregation on prefectural and county scales. ConclusionMAUP effects have substantive implications for understanding and decision-making in the arrangement of medicinal plant production regions. The county scale proves to be the most sensitive and explanatory level for analyzing the spatial pattern of P. heterophylla production regions， providing a critical foundation for habitat modeling， suitability evaluation， and ecological cultivation planning of medicinal plants.

BACKGROUND:Iron overload is an independent factor inducing osteoporosis,but the action mechanism is currently unclear.Therefore,exploring the effects of iron overload on osteoblast-related cells will help to deeply understand the pathogenesis of osteoporosis and provide potential strategies for osteoporosis treatment.OBJECTIVE:To explore the effects of iron overload environment on osteoblast precursor cell activity,ferroptosis,and osteogenic differentiation.METHODS:Osteoblast precursor cells(MC3T3-E1 cells)were divided into blank group,iron overload group,fer-1 group,and deferoxamine group.The iron overload group was treated with 300 μmol/L ammonium ferric citrate in the culture medium for 48 hours to simulate the iron overload microenvironment.The cells in fer-1 group and deferoxamine group were pretreated with 5 μmol/L antioxidant fer-1 and 5 μmol/L deferoxamine for 8 hours,respectively,and then added with 300 μmol/L ammonium ferric citrate for 48 hours.CCK-8 assay was used to determine the cell viability.Intracellular reactive oxygen species levels were detected employing a reactive oxygen species fluorescent probe.Changes in mitochondrial membrane potential were monitored with a mitochondrial membrane potential fluorescent probe.Mitochondrial morphology was observed employing transmission electron microscopy.Cellular glutathione levels were measured with a reduced glutathione colorimetric assay kit.Lipid peroxidation levels were assessed with a malondialdehyde colorimetric assay kit.Cellular ferrous ion levels were determined with a ferrous ion colorimetric assay kit.The osteogenic and mineralization capabilities of the cells were verified by alkaline phosphatase staining and alizarin red staining.Collagen secretion ability was detected using Sirius Red staining.The expression of osteogenic/ferroptosis-related genes and proteins was examined through reverse transcription quantitative polymerase chain reaction and western blot analysis.RESULTS AND CONCLUSION:(1)In an iron-overload environment,the mitochondrial membrane potential of cells decreased and their structure was compromised,with an elevation in intracellular lipid peroxidation levels and a downregulation of genes and proteins associated with ferroptosis resistance.However,pretreatment with fer-1 and deferoxamine led to an increase in mitochondrial membrane potential and partial restoration of morphology,a reduction in intracellular lipid peroxidation levels,and an upregulation of genes and proteins related to ferroptosis resistance.(2)In an iron-overload environment,the levels of cellular alkaline phosphatase,the formation of mineralized nodules,and the synthesis of collagen fibers were all found to be decreased.Pretreatment with fer-1 and deferoxamine was observed to upregulate the expression of osteogenic differentiation in cells.(3)In summary,iron overload could increase intracellular oxidative stress levels,mediate ferroptosis in MC3T3-E1 cells and inhibit osteogenic differentiation,thereby inducing osteoporosis.Therefore,maintaining iron homeostasis and inhibiting osteogenesis-related ferroptosis may be potential strategies to prevent or treat osteoporosis.

Objective:To explore the role and molecular mechanisms of S100A6 protein in neonatal meningitis caused by Streptococcus agalactiae. Methods:Human brain microvascular endothelial cells (HBMECs) were used as an in vitro experimental model, and siRNA was employed to construct S100A6 gene knockdown HBMECs strain. The S100A6 gene overexpression cell line was established by lentiviral transfection method. Western blot was used to detect the expression level of S100A6 protein in HBMECs after Streptococcus agalactiae infection, and the change in intracellular inflammatory cytokine protein levels after S100A6 gene knockdown or overexpression. A neonatal bacterial meningitis model was established by injecting Streptococcus agalactiae suspension into the cisterna magna of neonatal Sprague-Dawley (SD) rats. HE staining was used to observe pathological changes in brain tissue; immunohistochemistry was used to detect the expression and distribution of S100A6 protein in brain tissue; Western blot and ELISA were used to measure S100A6 protein levels in cerebrospinal fluid (CSF). Results:Compared with the control group, the intracellular S100A6 protein level in HBMECs increased significantly following Streptococcus cgalactiae infection. After S100A6 gene knockdown, the invasion rate of Streptococcus agalactiae into the HBMECs was significantly reduced ( P<0.01), while intracellular TNF-α and IL-6 protein levels were elevated markedly ( P<0.01). In contrast, overexpression of S100A6 gene increased the invasion rate ( P<0.01) and notably decreased TNF-α and IL-6 protein levels ( P<0.001). In the neonatal SD rat bacterial meningitis model, HE staining revealed substantial neutrophil infiltration in brain tissue after Streptococcus agalactiae infection. Immunohistochemistry showed extensive deposition of S100A6 protein around the meninges, and significant expression of S100A6 protein was also detected in CSF. Conclusions:S100A6 protein is crucial in mediating neonatal meningitis caused by Streptococcus agalactiae infection. S100A6 gene knockdown promotes the production of intracellular inflammatory cytokines and reduces Streptococcus agalactiae invasion into cells, thereby alleviating bacteria-induced cellular damage. Additionally, the increased expression of S100A6 protein in brain tissue and CSF after Streptococcus agalactiae infection suggests its potential as a diagnostic biomarker for bacterial meningitis.

BACKGROUND:As a member of bone morphogenetic proteins,growth differentiation factor-5 shows promising potential in the application of cartilage and bone repair.The affinity of growth differentiation factor-5 onto bone tissue determines protein use efficiency,so it is of great significance to prepare growth differentiation factor-5 with bone targeting capability. OBJECTIVE:To modify growth differentiation factor-5 using bisphosphonates and investigate the effects of modified protein on the growth of preosteoblasts in mice. METHODS:Pamidronate disodium/growth differentiation factor-5 complex was prepared using chemical crosslinking to couple growth differentiation factor-5 with pamidronate disodium.The functional groups and structures of the complex were characterized using Fourier transform infrared spectroscopy and circular dichromatography.To determine the bone targeting in vitro,the binding of the modified growth differentiation factor-5 with calcium phosphate and in vitro release amount of growth differentiation factor-5 were measured with an ELISA kit.Growth differentiation factor-5(control group)and the pamidronate disodium/growth differentiation factor-5 complex(experimental group)were co-cultured with preosteoblasts MC3T3-E1.Individually cultured cells were blank controls.The effect of the complex on cell proliferation and differentiation was evaluated. RESULTS AND CONCLUSION:(1)The infrared spectroscopy and circular dichromatography results indicated that the bisphosphonate/growth differentiation factor-5 complex was successfully prepared without significant changes in the protein secondary structure.In vitro protein adsorption results showed that growth differentiation factor-5 adsorption on calcium phosphate was increased by about one time after coupling with a bisphosphonate.In the presence of cysteine,growth differentiation factor-5 could be released from the bisphosphonate/growth differentiation factor-5 complex.(2)CCK-8 assay results showed that the absorbance value of the experimental group cultured for 4 and 7 days was higher than that of the control group and blank control group(P<0.000 1).After 7 days of culture,the expression of alkaline phosphatase in the experimental group was significantly higher than that in the control group and blank control group(P<0.000 1).After 13 days of culture,the content of calcium nodules in the experimental group was significantly higher than that in the control group and the blank control group(P<0.000 1).The results of qRT-PCR showed that the mRNA expression of alkaline phosphatase,osteocalcin and Runx2 in the experimental group was higher than that in the control group and the blank control group after 7 days of culture(P<0.01,P<0.001,P<0.000 1).(3)These findings exhibit that bisphosphonate modification can enhance the binding capacity of growth differentiation factor-5 to calcium phosphate as well as improve its biological activity.

Periarticular fracture of the shoulder is a common type of fractures in the elderly. Postoperative adverse events such as internal fixation failure, humeral head ischemic necrosis and upper limb dysfunction occur frequently, which seriously endangers the exercise and health of the elderly. Compared with the fracture with normal bone mass, the osteoporotic periarticular fracture of the shoulder is complicated with slow healing and poor rehabilitation, so the clinical management becomes more difficult. At present, there is no targeted guideline or consensus for this type of fracture in China. In such context, experts from Youth Osteoporosis Group of Chinese Orthopedic Association, Orthopedic Expert Committee of Geriatrics Branch of Chinese Association of Gerontology and Geriatrics, Osteoporosis Group of Youth Committee of Chinese Association of Orthopedic Surgeons and Osteoporosis Committee of Shanghai Association of Chinese Integrative Medicine developed the Chinese expert consensus on the diagnosis and treatment of osteoporotic periarticular fracture of the shoulder in the elderly ( version 2023). Nine recommendations were put forward from the aspects of diagnosis, treatment strategies and rehabilitation of osteoporotic periarticular fracture of the shoulder, hoping to promote the standardized, systematic and personalized diagnosis and treatment concept and improve functional outcomes and quality of life in elderly patients with osteoporotic periarticular fracture of the shoulder.

TSCI have dyskinesia and sensory disturbance that can cause various life-threaten complications. The patients with traumatic spinal cord injury (TSCI), seriously affecting the quality of life of patients. Based on the epidemiology of TSCI and domestic and foreign literatures as well as expert investigations, this expert consensus reviews the definition, injury classification, rehabilitation assessment, rehabilitation strategies and rehabilitation measures of TSCI so as to provide early standardized rehabilitation treatment methods for TSCI.