BACKGROUND:The extracellular-regulated protein kinase 5(ERK5)signaling protein is essential for the survival of organisms,and resveratrol can promote osteoblast proliferation through various pathways.However,whether resveratrol can regulate osteoblast function through the ERK5 signaling protein needs further verification. OBJECTIVE:To explore the regulatory effect of ERK5 on the proliferation of MC3T3-E1 cells and related secreted proteins,and to further verify whether resveratrol can complete the above process by activating ERK5. METHODS:Mouse MC3T3-E1 preosteoblasts were treated with complete culture medium,XMD8-92(an ERK5 inhibitor),epidermal growth factor(an ERK5 activator),resveratrol alone,XMD8-92+EGF,and resveratrol+XMD8-92,respectively.Western blot assay was used to detect the expression of ERK5 and p-ERK5 proteins,proliferation-related proteins Cyclin D1,CDK4 and PCNA,and osteoblast-secreted proteins osteoprotegerin and receptor activator of nuclear factor-κB ligand in MC3T3-E1 cells of each group.The fluorescence intensity of ERK5,osteoprotegerin and receptor activator of nuclear factor-κB ligand in each group was detected by cell immunofluorescence staining,and cell proliferation was detected by EdU staining,respectively.The appropriate concentration and time of resveratrol intervention in MC3T3-E1 cells were determined by cell morphology observation and cell counting kit-8 assay. RESULTS AND CONCLUSION:The activation of ERK5 signaling protein could effectively promote the proliferation of MC3T3-E1 cells,up-regulate the osteoprotegerin/receptor activator of nuclear factor-κB ligand ratio.The appropriate concentration and time for resveratrol intervention in MC3T3-E1 cells was 5 μmol/L and 24 hours,respectively.Resveratrol could activate ERK5 signaling protein,thereby promoting osteoblast proliferation and up-regulating the osteoprotegerin/RANKL ratio.All these results indicate that resveratrol can promote the proliferation of MC3T3-E1 cells and up-regulate the osteoprotegerin/RANKL ratio by activating the ERK5 signaling protein.

BACKGROUND:The imbalance between bone resorption and bone formation in microgravity environments leads to significant bone loss in astronauts.Current research indicates that bone loss under microgravity conditions is the result of the combined effects of various cells,tissues,and systems. OBJECTIVE:To review different biological effects of microgravity on various cells,tissues,or systems,and summarize the mechanisms by which microgravity leads to the development of osteoporosis. METHODS:Databases such as PubMed,Web of Science,and the Cochrane Database were searched for relevant literature from 2000 to 2023.The inclusion criteria were all articles related to tissue engineering studies and basic research on osteoporosis caused by microgravity.Ultimately,85 articles were included for review. RESULTS AND CONCLUSION:(1)In microgravity environment,bone marrow mesenchymal stem cells tend to differentiate more into adipocytes rather than osteoblasts,and hematopoietic stem cells in this environment are more inclined to differentiate into osteoclasts,reducing differentiation into the erythroid lineage.At the same time,microgravity inhibits the proliferation and differentiation of osteoblasts,promotes apoptosis of osteoblasts,alters cell morphology,and reduces the mineralization capacity of osteoblasts.Microgravity significantly increases the number and activity of osteoclasts.Microgravity also hinders the differentiation of osteoblasts into osteocytes and promotes the apoptosis of osteocytes.(2)In a microgravity environment,the body experiences changes such as skeletal muscle atrophy,microvascular remodeling,bone microcirculation disorders,and endocrine disruption.These changes lead to mechanical unloading in the bone microenvironment,insufficient blood perfusion,and calcium cycle disorders,which significantly impact the development of osteoporosis.(3)At present,the mechanism by which microgravity causes osteoporosis is relatively complex.A deeper study of these physiological mechanisms is crucial to ensuring the health of astronauts during long-term space missions,and provides a theoretical basis for the prevention and treatment of osteoporosis.

BACKGROUND:Studies have confirmed that up-regulation of microRNA-140 expression can partially inhibit osteoarthritis-like changes in knee cartilage tissues and cells and delay the progression of osteoarthritis,suggesting that microRNA-140 is involved in the pathogenesis of osteoarthritis.OBJECTIVE:To further analyze the mechanism of microRNA-140 involvement in osteoarthritis by loading exosomes overexpressing microRNA-140 with sodium alginate/collagen hydrogel.METHODS:Lentivirus was used to infect rat bone marrow mesenchymal stem cells to overexpress microRNA-140,then exosomes were isolated and exosomes overexpressing microRNA-140 were obtained.Sodium alginate/collagen hydrogels loaded with exosomes were prepared.Thirty-two SD rats were randomly divided into four groups,with 8 rats in each group.Normal control group did not receive any treatment.The osteoarthritis model was established by injecting sodium iodoacetate into the knee cavity in the osteoarthritis group,the non-transfected exosome group and the transfected exosome group.Two weeks later,PBS was injected into the knee cavity in the osteoarthritis group.Sodium alginate/collagen hydrogel carrying non-overexpressing microRNA-140 and overexpressing microRNA-140 exosomes were injected into the knee cavity of the non-transfected exosome group and transfected exosome group.At 6 weeks after modeling,the threshold of mechanical foot withdrawal response,the concentration of inflammatory factors in synovial fluid,the expression of chondrogen-related genes,the histological changes of knee cartilage and the expression of pyroptosis related proteins were detected in rats.RESULTS AND CONCLUSION:(1)Compared with normal control group,the threshold value of mechanical stimulation foot contraction response,type Ⅱ collagen,SOX9 mRNA expression levels,and Type Ⅱ collagen immunofluorescence intensity were decreased in the osteoarthritis group(P<0.05),and proinflammatory cytokine levels were increased in synovial fluid(P<0.05).The mRNA expressions of matrix metalloproteinase 13 and a disintegrin and metalloproteinase with thrombospondin motifs-5(ADAMTS-5)were increased(P<0.05),and the protein expression levels of NLRP3,ASC,GSDMD p30,caspase-1 p20,interleukin-1β,and interleukin-18 were increased(P<0.05).Immunofluorescence intensity of GSDMD and cleaved caspase-1 was increased(P<0.05),and cartilage tissue was severely damaged.(2)Compared with osteoarthritis group,the threshold value of mechanical stimulation foot contraction response,type Ⅱ collagen,SOX9 mRNA expression levels,and type Ⅱ collagen immunofluorescence intensity in the non-transfected and transfected exosome groups were increased(P<0.05);proinflammatory cytokine levels were decreased in synovial fluid(P<0.05).The mRNA expression of matrix metalloproteinase 13 was decreased(P<0.05),and the protein expression levels of NLRP3,ASC,GSDMD p30,caspase-1 p20,interleukin-1β,and interleukin-18 were decreased(P<0.05).The immunofluorescence intensity of GSDMD and cleaved caspase-1 decreased(P<0.05),and the cartilage tissue damage was reduced(P<0.05),and the effect was stronger in the transfected exosome group.(3)These results conclude that microRNA-140 can reduce the pain response of rats with osteoarthritis by inhibiting inflammation,maintaining cartilage homeostasis,and inhibiting cartilaginous pyroptosis,thereby reducing cartilage damage and playing a therapeutic role in osteoarthritis.

BACKGROUND:Nerve growth factor plays an important role in the physiological and pathological processes of bone tissue.Systematic analysis of the effects of nerve growth factor on bone tissue is of great significance in both tissue engineering and clinical treatment.OBJECTIVE:To investigate the regulation of bone formation process by nerve growth factor through pathways such as bone tissue cells and bone nerve-vessel coupling,as well as to study the role of nerve growth factor in the pathological process of bone-related diseases.METHODS:The authors searched for relevant articles in CNKI,WanFang,and PubMed with the keywords of"nerve growth factor,TrkA,NGF,bone,cartilage"in Chinese and English.A total of 2 925 articles were initially retrieved.After screening,116 articles were incorporated into this review.RESULTS AND CONCLUSION:Nerve growth factor can be expressed by bone,cartilage,nerve,vessel and other tissue cells.At the same time,nerve growth factor can play a regulatory role on these cells.Through a variety of secretion and regulation methods,nerve growth factor plays a role as a signal transduction factor within bone tissue and between bone,nerve and blood vessel tissues.By promoting the proliferation and differentiation of bone marrow mesenchymal stem cells,nerve growth factor promotes bone formation and bone repair.Nerve growth factor has multi-directional regulatory effects on bone tissue through its effects on osteoclasts.Meanwhile,nerve growth factor is highly correlated with the occurrence and development of many orthopedic diseases and may provide new clinical therapeutic ideas.The study of nerve growth factor is one of the important directions to understand the physiological and pathological processes of bone.

BACKGROUND:Wolff's law points out that the lack of mechanical stress in the body will lead to the degradation of the microstructure of bone tissue,mass loss,and metabolic disorders,and eventually lead to osteoporosis,which suggests that mechanical stress plays an important role in the growth,reconstruction,and formation of bone tissue.At present,the relevant studies concerning mechanical stress on osteoblasts mainly focus on fluid shear force,but it is difficult to intervene in vivo.Meanwhile,some studies have found that compressive stress can also play a similar role in fluid shear force to a certain extent.Exploring the mode of action and influence of compressive stress on cells in vitro experiments can enrich the interaction relationship between mechanical stress and cells.It helps provide a theoretical basis for studies of metabolic bone diseases,including osteoporosis,and other diseases.OBJECTIVE:To review in vitro experiments,the application of compressive stress to cells,different biological behaviors caused by cells,the possible signaling pathways,and possible future applications.METHODS:We searched PubMed,Web of Science,CNKI,and WanFang databases from January 2000 to March 2024 to include all articles related to compressive stress on cells,including basic research and microscopic mechanism studies,using search terms"compressive stress,mechanical stress,hydrostatic pressure,cell"in Chinese and English.Finally,the 63 included articles were reviewed.RESULTS AND CONCLUSION:(1)There are various ways to apply compressive stress,and different experimental equipment has different ways of pressurizing cells,so it is necessary to further standardize the experimental equipment,standardize the pressurization unit,reduce the confounding factors,and make the reference and comparability between different experimental groups.(2)Compressive stress can cause changes in cell proliferation,differentiation,autophagy,apoptosis,migration,etc.,and the effect of compressive stress is time-or dose-dependent in most cases.(3)At present,most in vitro experimental studies have shown that compressive stress may mainly act on osteoblasts through MAPK signaling pathway and Wnt/β-catenin signaling pathway,causing osteoblasts to produce different responses.(4)The effect of compressive stress on different cells is not the same,and its possible biological effects need to be studied.(5)Further research on compressive stress is helpful to provide a theoretical basis for treatment in orthopedics,stomatology,tumors and other fields,and gentle disinfection using hydrostatic pressure is a promising disinfection method.

Objective:To develop rat models of oral mucosa ulcer using distinct experimental methodologies,fulfilling research requirements and adhering to the ethical standards for animal care.Methods:96 SD rats were randomly allocated into groups.The rats in control group(n=8)were regularly fed without other treatment.Those in chemical cauterization groups were treated by 20％,40％,60％of glacial acetic acid(GAA)on oral mucosa(n=8);in mechanical damage groups by 30 000 r/min high speed drill induced trauma of 10,20 and 30 mm2 respectively(n=8);in ionizing radiation groups were treated with 10,12,15,20 and 30 Gy on the mucosa respectively(n=8).After the ulcer was appeared,the morphology of the mucosa were observed,the mucosal tissue lesions were examined by HE,Masson and immunofluorescence staining,the expression of TNF-α and IL-1β were detected by qPCR and ELISA respectively,and the body conditions such as diet and body weight of the rats were observed,the pain,dis-tress and discomfor of the rats were evaluated by MORTON&Griffits Guidelines.Results:40％and 60％GAA,20 mm2 and 30 mm2 friction damage and ionizing radiation of 12 Gy or greater may induce oral mucosa ulcer with a diseas coruse of 6-7 d in SD rats.TNF-α and IL-1β mRNA expression in the damaged tissue,the related protein expression in blood serum of the rats were in-creased.MORTON&Griffits Guidelines analysis showed 40％GAA,20 mm2 friction damage and 12 Gy ionizing radiation induced the lowest scores of pain,distress and discomfort of the rats with compatible oral mocosa ulcere induced by the relevat treatment.Conclusion:40％GAA,20 mm2 of friction damage and 12 Gy of ionizing radiation can reliably establish oral mucosa ulcer models and minimize adverse effects on SD rats,and accord with ethical standards of 3R for laboratory animal.

In the context of the development of transplant oncology,it is of great clinical significance to find a drug with both antitumor and immunosuppressive effects for liver transplantation patients with hepatocellular carcinoma(HCC).The antitumor effect of ginkgolic acid(GA)has been confirmed,and some studies suggest that GA may also have an immunosuppressive effect.The immunosuppressive effect of GA was evaluated by histopathology,T-cell subpopulation,and cytokine detection in rat liver transplantation and mouse cardiac transplantation models,and transcriptomic and metabolomic analysis was used to explore the underlying mechanism of the GA immunosuppressive effect.Metabolites,activation,and ferroptosis markers of CD8+T cells were detected in vivo and in vitro.Based on rat liver transplantation and mouse cardiac transplantation models,the immunosuppressive effect of GA was first confirmed by histopathology,T-cell subpopulation,and cytokine detection.In the mouse cardiac transplantation model,transcriptomics combined with metabolomics demonstrated for the first time that GA inhibited lactate dehydrogenase A(LDHA)expression and pyruvate metabolism in CD8+T cells.It was confirmed in vivo and in vitro that GA inhibited pyruvate metabolism of CD8+T cells through LDHA,inhibiting their activation and inducing ferroptosis.Over-expression of LDHA partially reversed the effect of GA on the metabolism,activation,and ferroptosis of CD8+T cells in vitro.GA mediates metabolic reprogramming through LDHA to inhibit the activation and induce ferroptosis of CD8+T cells to exert an immunosuppressive effect,which lays an experimental foundation for the future clinical application of its immunosuppressive effect.

Objective To investigate the effects of periodontitis induced by Prevotella nigrescens(Pn)combined with ligation on cognitive functions in mice.Methods Twenty-four C57BL/6J mice were randomly divided into control group,ligation group,and ligation+Pn treatment(P+Pn)group.Experimental periodontitis was induced by silk ligation of the first molars followed by topical application of Pn for 6 weeks.After modeling,alveolar bone resorption was assessed using micro-CT and histological analysis.Learning and memory abilities of the mice were evaluated using open field test(OFT),novel object recognition test(NORT),and Morris water maze test(MWM).Seven weeks after the start of modeling,the mice were sacrificed for examining histopathological changes in the hippocampus using HE and Nissl staining.Results After 6 weeks of molar ligation,micro-CT revealed horizontal alveolar bone resorption and furcation exposure in the mice,and histological analysis showed apical migration of the junctional epithelium,epithelial ridge hyperplasia,and lymphocyte infiltration,and these changes were obviously worsened in P+Pn group.Alveolar bone height decreased significantly in both ligation groups compared to the control group.Cognitive tests showed that the mice in both of the ligation groups traveled shorter distances in OFT,showed reduced novel object preference in NORT,and exhibited longer escape latencies in MWM,and the mice in P+Pn group had significantly poorer performances in the tests.Histologically,obvious neuronal cytoplasmic degeneration,necrosis,nuclear pyknosis,vacuolation,and reduced Nissl bodies and viable neurons were observed in the hippocampal regions of the mice in the two ligation groups.Conclusion Pn infection aggravates alveolar bone destruction,accelerates necrosis and causes morphological abnormalities of neuronal cells in the hippocampus to reduce cognitive functions of mice with periodontitis.

Refinement and standardisation of the management of clinical diagnostic and treatment operations is a key aspect of achieving high-quality development in hospitals.By analysing the management status quo of clinical diagnosis and treatment operations in hospitals,it combed the problems existing in this field.Based on the closed-loop management model,it proposed measures and recommendations to promote the continuous optimisation of the management of clinical diagnostic operations in hospitals.Hospitals should establish hospital-level operation catalog and conduct classified management,authorize operators and dynamically adjust them,carry out operation quality management,pay attention to information management of operation management,and combine operation management with physician performance management.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of liquiritin,liquiritin apioside,verbascoside,narirutin,isoacteoside,apigetrin,hesperidin,isoliquiritin,ononin,liquiritigenin,glycyrrhizic acid,isoliquiritigenin,honokiol,obovatol,pogostone and magnolol in Jiawei Huoxiang Zhengqi Soft Capsules.METHODS The analysis was performed on a 40 ℃ thermostatic ZORBAX Eclipse Plus C18 column(2.1 mm×100 mm,1.8 μm),with the mobile phase comprising of 0.1％formic acid-acetonitrile flowing at 0.4 mL/min in a gradient elution manner,and electron spray ionization source was adopted in positive and negative ion scanning with multiple reaction monitoring mode.RESULTS Sixteen constituents showed good linear relationships within their own ranges(r＞0.990 0),whose average recoveries were 83.74％-105.12％with the RSDs of 1.10％-4.8％.CONCLUSION This accurate,sensitive,stable and reproducible method can provide a reference for the overall quality control of Jiawei Huoxiang Zhengqi Soft Capsules.