BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

BACKGROUND:Naringin has been shown to promote the proliferation and osteogenic differentiation of bone marrow derived mesenchymal stem cells,making it a potential candidate for treating osteoporosis andenhancing fracture healing.However,its clinical application is limited by its low bioavailability.OBJECTIVE:To prepare chitosan/β-tricalcium phosphate scaffolds loaded with naringin and characterize their biological properties.METHODS:Chitosan/β-tricalcium phosphate scaffolds were prepared by freeze-drying and chemical crosslinking.The chitosan/β-tricalcium phosphate scaffolds were immersed in anhydrous ethanol solution containing naringin for 3 hours.After vacuum cold drying,chitosan/β-tricalcium phosphate/naringin scaffolds were obtained.The pore size,porosity,swelling rate,degradation rate,mechanical properties,and in vitro release capacity of naringin of the scaffolds were characterized.Rat bone marrow mesenchymal stem cells were inoculated on the surface of chitosan/β-tricalcium phosphate scaffolds and chitosan/β-tricalcium phosphate/naringin scaffolds,respectively,and cell proliferation,adhesion,activity and alkaline phosphatase activity after osteogenic differentiation were detected.RESULTS AND CONCLUSION:(1)The results of scanning electron microscopy showed that the naringin-chitosan/β-tricalcium phosphate composite scaffold had a porous mesh structure.The average pore diameter was(106.82±25.22)μm;the porosity was(76.26±4.81)％;24-hour swelling rate was(796.17±31.76)％;in vitro degradation rate of 7.71％at 4 weeks,and naringin could be slowly released in vitro for 9 days.There was no significant difference in the average pore size,porosity,24-hour swelling rate,in vitro degradation rate,compression strength and compression modulus at 4 weeks between the chitosan/β-tricalcium phosphate scaffold and the chitosan/β-tricalcium phosphate scaffold(P＞0.05).(2)Rat bone marrow mesenchymal stem cells adhered well to the surfaces of the two scaffolds and had good activity.Compared with the chitosan/β-tricalcium phosphate scaffold,the chitosan/β-tricalcium phosphate/naringin scaffold promoted the proliferation of rat bone marrow mesenchymal stem cells(P＜0.05),and increased the alkaline phosphatase activity of bone marrow mesenchymal stem cells after osteogenic differentiation(P＜0.05).(3)The results show that the chitosan/β-tricalcium phosphate/naringin scaffolds exhibit favorable physical properties and can effectively promote the adhesion,proliferation,and osteogenic differentiation of bone marrow-derived mesenchymal stem cells.

BACKGROUND:Studies have shown that rheumatoid arthritis and osteoporosis are positively correlated,but the causal relationship and related mechanisms have not yet been confirmed.With the cross-fertilization of computer science and life sciences,Mendelian randomization and bioinformatics analyses based on genome-wide association study(GWAS)and transcriptome sequencing data can assess the causal relationship between two diseases,explore the related mechanisms,and mine the therapeutic targets,which will be beneficial to the precision treatment of rheumatoid arthritis combined with osteoporosis.OBJECTIVE:To explore the causal relationship between rheumatoid arthritis and osteoporosis using two-sample Mendelian randomization and to mine potential co-morbid targets and potential targeted drugs through summary-data-based Mendelian randomization and bioinformatics analyses,aiming to provide theoretical basis for mechanism exploration and precision treatment in the field of rheumatoid arthritis combined with osteoporosis.METHODS:(1)Firstly,GWAS data of rheumatoid arthritis,osteoporosis,and cis-expression quantitative trait locus(cis-eQTL)in Asian and European populations were downloaded from the GWAS Catalog,IEU Open GWAS,FinnGen,and eQTLGen databases,and were used for two-sample Mendelian randomization analysis and summary-data-based Mendelian randomization analysis.(2)Transcriptome sequencing data of rheumatoid arthritis(GSE93272 and GSE15573)were downloaded from the GEO database for bioinformatics analysis.(3)Subsequently,forward and inverse Mendelian randomization analyses between rheumatoid arthritis and osteoporosis were performed,and inverse variance weighted was used as the main metric for the analyses,and the results were corroborated with MR Egger,simple mode,weighted median and weighted mode.(4)Then,the genes closely related to rheumatoid arthritis and osteoporosis were identified based on the summary-data-based Mendelian randomization analysis,and the co-disease targets of rheumatoid arthritis and osteoporosis were mined based on cross-analysis.Meanwhile,the biological functions of the co-morbid targets were verified based on bioinformatics analysis and cellular experiments.(5)In addition,a rheumatoid arthritis risk prediction nomogram was constructed based on DYRK2,and its prediction performance was verified by receiver operating characteristic curve,correction curve and decision curve.Finally,the target potential drugs were mined based on Enrichr database and molecular docking was performed.RESULTS AND CONCLUSION:(1)Forward Mendelian randomization analysis of rheumatoid arthritis and osteoporosis showed statistically significant results except for GCST90044540 and GCST90086118,and all other results indicated a significant causal relationship and positive correlation between rheumatoid arthritis and osteoporosis.(2)Inverse Mendelian randomization analysis suggested that no significant causal relationship was seen between osteoporosis and rheumatoid arthritis.(3)Summary-data-based Mendelian randomization analysis identified a total of 412 and 344 genes positively associated with rheumatoid arthritis and osteoporosis,and 421 and 347 genes negatively associated.Based on the cross-analysis,26 co-morbid genes were subsequently obtained.Among them,DYRK2 was a potential therapeutic target,and subsequent bioinformatics analysis and cellular experiments confirmed its important role in the progression of rheumatoid arthritis and osteoporosis.(4)Furthermore,the constructed nomogram has excellent predictive performance.Finally,four potential DYRK2-targeting drugs(undecanoic acid,metyrapone,JNJ-38877605,and ACA)were discovered and molecular docking also demonstrated reliable targeting ability.(5)In conclusion,based on GWAS data from Asian and European populations,we successfully demonstrated that rheumatoid arthritis and osteoporosis are causally related at the genetic level,DYRK2 is a potential therapeutic target,and four small molecules are potential target drugs.

BACKGROUND:In the field of tissue engineering,decellularized scaffolds are widely used owing to their biocompatibility.Nonetheless,these scaffolds frequently encounter the limitation of inadequate cell infiltration due to their densely structured composition.Using laser micro-patterning technology for structural modification can improve cell adhesion and proliferation.OBJECTIVE:To summarize the research progress of laser microporous decellularized scaffolds in tissue regeneration.METHODS:Related literature was searched in PubMed and CNKI databases.The Chinese and English search terms were"decellularized scaffold,laser micro-patterning technology,laser microporous decellularized scaffold,extracellular matrix,laser drilling,tissue regeneration."References were screened according to inclusion and exclusion criteria,and 65 articles were finally included for analysis and discussion.RESULTS AND CONCLUSION:(1)Laser micro-patterning technology can selectively remove tissues to achieve scaffold modification.Laser treatment can have controllable effects on the pore structure,mechanical properties and cell permeability of the scaffold.(2)To obtain the optimal cell integration and remodeling effect,factors such as scaffold pretreatment,laser and decellularization process sequence,laser parameter setting,decellularization process and pore structure should be considered.(3)At present,the application of laser microporous decellularized scaffolds has shown that it can promote tissue repair,and it is also necessary to solve the problem of tissue thermal damage.Depending on the absorption of different wavelengths of laser light by the tissue,a reasonable selection of laser type is a feasible solution.(4)Tissue damage repair by laser microporous decellularized scaffold is expected to achieve clinical transformation,and optimizing laser technology and carrying out larger scale biosafety testing are future research directions.

BACKGROUND:The exact pathogenesis of temporomandibular joint osteoarthritis is currently unclear.Traditional clinical treatment strategies for temporomandibular joint osteoarthritis are symptomatic treatments such as pain relief and reduction of inflammation,which can stop the progression of the disease to a certain degree but cannot reverse the destruction of the cartilage.Cartilage degeneration,as one of the most prominent pathologic features in the development of temporomandibular joint osteoarthritis,has been the subject of an increasing number of studies that focus on its pathogenesis.Consequently,we hope to provide an ideal radical solution for the regeneration of the temporomandibular joint.OBJECTIVE:To review the progress of research on cartilage degeneration in temporomandibular joint osteoarthritis.METHODS:The search terms were"temporomandibular joint osteoarthritis,degradation of cartilage matrix,synovitis,oxidative stress,chondrocyte hypertrophy,chondrocyte apoptosis,ferroptosis,autophagy,angiogenesis,extracellular vesicles"in Chinese and English.Literature search was conducted in PubMed database and CNKI,and the time limit for the search was from January 2004 to October 2024.Screening was performed by analyzing and reading the literature,and according to the inclusion and exclusion criteria,81 papers were finally included for review.RESULTS AND CONCLUSION:(1)Increased secretion of cartilage matrix degrading enzymes causes degradation of the cartilage matrix,leading to cartilage degeneration.(2)Synovitis promotes cartilage degeneration through macrophage M1-type polarization and production of inflammatory mediators.(3)Oxidative stress promotes cartilage degeneration by exacerbating the inflammatory response through overproduction of reactive oxygen species.(4)Chondrocyte phenotypic changes and death lead to the decrease of cartilage matrix synthesis,resulting in cartilage degeneration.(5)Blood vessels of subchondral bone penetrate the calcified cartilage layer to reach the superficial cartilage layer,which destroys the cartilage structure and leads to cartilage degeneration.(6)Bioactive substances carried by serum-derived extracellular vesicles in inflammatory states also promote cartilage degeneration in temporomandibular joint osteoarthritis.

BACKGROUND:Alzheimer's disease has been associated with sarcopenia,but a causal relationship has not been established.Exploring the causal relationship between the two most common disability-burdening diseases in the aging population-Alzheimer's disease and sarcopenia-and their potential mediating factors holds certain implications for further alleviating the healthcare costs and socioeconomic burden for older adults in China.OBJECTIVE:To explore the potential causal relationship between Alzheimer's disease and sarcopenia in the general population using a Mendelian randomization study and to explore the role of body mass index in this context.METHODS:Two-sample Mendelian randomization analysis based on published genome-wide association studies(GWAS)were used to infer causality,and univariate Mendelian randomization and mediation analyses were used in the study design.Through the Integrative Epidemiology Unit(IEU)database,ieu-b-2 was selected as the Alzheimer's disease dataset(sample size:63 926),ieu-b-4816 as the body mass index dataset(99 998),ebi-a-GCST90000027 as the appendicular lean mass dataset(244 730),ukb-b-7478 as the left hand grip strength dataset(461 026),ukb-b-10215 as the right hand grip strength dataset(461 089)and ukb-b-4711 as the walking pace dataset(459 915).Inverse-variance weighting was used as the primary analysis method,and the results were validated by pleiotropy and heterogeneity analysis.The Steiger Directionality Test was performed to validate the reasonableness of the causal direction.RESULTS AND CONCLUSION:(1)The Mendelian randomization analyses provided evidence that Alzheimer's disease predicted the risk of appendicular lean mass[odds ratio(OR)=1.009;95％confidence interval(Cl),1.001-1.017;P=0.023),and walking pace(OR=1.010;95％Cl,1.003-1.017;P=0.008).No correlation with hand grip strength was observed.(2)Alzheimer's disease was negatively correlated with body mass index(OR=0.893;95％Cl,0.811-0.984;P=0.022);body mass index was positively correlated with appendicular lean mass(OR=1.084;95％Cl,1.031-1.141;P=0.002)and negatively correlated with walking pace(OR=0.975;95％Cl,0.969-0.980;P＜0.001).(3)Mediation analyses showed that the causal relationship between Alzheimer's disease and appendicular lean mass and walking pace was partially mediated by body mass index,with the proportion of mediations being 50.25％and 32.11％,respectively.(4)The results of this study suggest that based on large-scale population studies,genetic prediction of Alzheimer's disease is a potential risk factor for sarcopenia,in which body mass index plays an important mediating role.This suggests that in clinical practice,attention should be paid to the muscle condition of patients with Alzheimer's disease,and weight management should be implemented,as maintaining a body mass index within the normal high range may have a preventive effect on the occurrence of sarcopenia in patients with Alzheimer's disease.However,further research is needed to verify the applicability of this conclusion to other ethnic groups.This study utilized an international public database for analysis,providing a reference for research on the correlation between Alzheimer's disease and sarcopenia in the Chinese population.It also highlights the significant mediating role of body mass index,offering insights for further prevention and treatment of sarcopenia among Chinese individuals.

BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P＜0.01).After 7 days(P＜0.01,P＜0.01)and 10 days(P＜0.01,P＜0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P＜0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P＜0.05,P＜0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P＜0.01,P＜0.01,P＜0.01,P＜0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.

BACKGROUND:Studies have confirmed that Pterocarya hupehensis skan total flavonoids(PHSTF)can improve the level of collagen-induced arthritis in rats,but there is still a lack of research on the regulation of Wnt/β-catenin signaling pathway in fibroblast-like synoviocytes and its effect on related cell functions.OBJECTIVE:To investigate the effect and mechanism of PHSTF on lipopolysaccharide-induced proliferation,migration and apoptosis of fibroblast-like synoviocytes based on the Wnt/β-catenin signaling pathwayMETHODS:Fibroblast-like synoviocytes were divided into control group,lipopolysaccharide group,lipopolysaccharide+low-,medium-,and high-dose PHSTF groups(10,20,and 40 μg/mL),lipopolysaccharide+Wnt pathway inhibitor DKK1 group,and lipopolysaccharide+Wnt pathway inhibitor DKK1+high-dose PHSTF group(40 μg/mL).The cell counting kit-8 method was used to detect the effect of PHSTF on the viability of fibroblast-like synoviocytes,and the final drug concentration and time were screened.Flow cytometry was used to detect the apoptosis of fibroblast-like synoviocytes.Cell scratch assay,EDU staining and cell cloning assay were used to detect the migration and proliferation of fibroblast-like synoviocytes.Western blot assay was used to detect the protein expression levels of Wnt3a,β-catenin,tumorigenic genes,matrix metalloproteinase 2,matrix metalloproteinase 9,Bax and Bcl-2 in fibroblast-like synoviocytes.RESULTS AND CONCLUSION:(1)Compared with the control group,the cell viability decreased significantly when the concentration of PHSTF was＞40 μg/mL(P＜0.01).Therefore,the drug concentration of≤40 μg/mL was selected for subsequent experiments.(2)Compared with the lipopolysaccharide group,the wound healing rate,cell clone formation rate and the number of EDU-positive cells in the low-,medium-and high-dose PHSTF groups were significantly reduced,while the apoptosis rate was significantly increased(P＜0.05-0.01).(3)Western blot results showed that compared with the lipopolysaccharide group,low-,medium-and high-dose PHSTF significantly inhibited cellular Wnt3a,β-catenin,cellular tumorigenic genes,matrix metalloproteinase 2,matrix metalloproteinase 9,and Bcl-2 protein expression,and promoted the expression of Bax protein(P＜0.01).(4)Compared with the DKK1 group,the combination of DKK1 and high-dose PHSTF significantly inhibited the protein expression of Wnt3a,β-catenin,matrix metalloproteinase 2,matrix metalloproteinase 9 and Bcl-2 protein expression and promoted the protein expression of Bax(P＜0.01).To conclude,PHSTF may inhibit the proliferation and migration of fibroblast-like synoviocytes and promote apoptosis by inhibiting the Wnt/β-catenin signaling pathway.

BACKGROUND:Several observational studies have found a strong association between thyroid function and its related disorders and osteoporosis,but the causal relationship is unclear.OBJECTIVE:To ascertain the causal relationship between genetically predicted thyroid function and its associated disorders,as well as osteoporosis,through the Mendelian randomization analysis with extensive pooled genetic data.METHODS:Pooled data from genome-wide association studies were employed to investigate the causal relationship between thyroid function and its associated disorders and osteoporosis.This was achieved through the utilization of the inverse variance weighting method as the primary Mendelian randomization analysis method,in conjunction with the MR-Egger method,weighted median method,simple model method,and weighted model method.A two-step mediated Mendelian randomization analysis was used to calculate the mediating effect of drug-mediated thyroid dysfunction on osteoporosis and the mediating proportion.Subsequently,sensitivity analyses were conducted using the MR-Egger intercept test and MR-PRESSO to detect multiplicity,Cochran's Q test to detect heterogeneity,and leave-one-out to perform sensitivity analyses.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method showed that thyroid function had an effect on bone mineral density,and that thyrotropin,free triiodothyronine on bone mineral density,free thyroxine,and subclinical hyperthyroidism all had a causal effect on bone mineral density.(2)In addition,mediation analyses revealed a potential mediating effect of carbimazole in the causal relationship between hyperthyroidism and the risk of developing osteoporosis,as well as a potential mediating effect of levothyroxine sodium in the causal relationship between hypothyroidism and the risk of developing osteoporosis.(3)In conclusion,thyrotropin,which is high in the normal range,has been demonstrated to increase bone mineral density.Conversely,free triiodothyronine and free thyroxine,which are also high within the normal range,as well as subclinical hyperthyroidism,have been shown to decrease bone mineral density.The risk of developing osteoporosis is partially mediated by the pathway of taking the therapeutic medication in the context of pharmacologic treatment of thyroid dysfunction.(4)The present study primarily focuses on European population data.However,given the commonality of the genetic background and the generalizability of genome-wide data analysis methods,it is of significant importance to explore the pathogenesis of osteoporosis in the Chinese population,develop effective interventions,and provide genetic counseling.

Alzheimer's disease （AD） is a common type of dementia， primarily characterized by cognitive and behavioral impairments as well as deficits in learning and memory. The progression of AD has imposed a significant economic burden on society and families. However， its exact pathogenesis has not yet been fully elucidated. Currently， available therapeutic drugs are limited and are often accompanied by serious adverse effects. Traditional Chinese medicines （TCMs） and their extracts are mostly natural products and possess advantages such as multi-pathway regulation and relatively few adverse reactions. Experimental studies have shown that TCMs exhibit great potential in the prevention and treatment of AD. For example， Huanglian Jieduang， Danggui Shaoyaosan， Kaixin San， Liuwei Dihuangwan， Buyang Huanwutang， as well as Ginseng Radix et Rhizoma， Astragali Radix， Uncariae Ramulus cum Uncis， Coptidis Rhizoma， Gardeniae Fructus， Ginkgo Folium， Salviae Miltiorrhizae Radix et Rhizoma， and Curcumae Longae Rhizoma， can reduce β-amyloid deposition， inhibit excessive Tau protein phosphorylation， restore mitochondrial function， alleviate oxidative stress， suppress neuroinflammation and apoptosis， repair synaptic function， and improve gut microbiota. This article mainly summarizes the effects of several TCMs and compound prescriptions on AD， aiming to provide a reference for subsequent TCM-based treatment of AD.