Objective:To explore the correlation between weekend moderate-to-vigorous physical activity(MVPA), weekday sedentary behavior(SB)and the risk of frailty in the elderly population monitored by wearable devices, and to provide a scientific basis for lifestyle interventions for frailty in the elderly.Methods:This study was based on the data of the UK Biobank from 2013 to 2015.A cross-sectional study design was adopted, and 33, 212 elderly people aged 60 and above with complete physical activity monitoring data were selected.The Frailty Index(FI)constructed by the deficit accumulation method was used to assess the frailty status.The correlation between the combined effect of weekday SB and weekend MVPA and the frailty status was analyzed, and the differences between genders were explored.Results:There were significant differences in physical activity indicators among the elderly with different frailty statuses.As the degree of frailty increased, the MVPA-related indicators showed a downward trend, while the weekday SB time gradually increased.There were sex differences in physical activity patterns and frailties.Compared with women, men had longer SB time on weekdays, lower metabolic equivalent of weekly MVPA consumption, and higher MVPA time on weekends, but the frailties index of women was slightly higher than that of men.After adjusting for confounding factors, the frailty risks for men and women in the subgroup with the lowest weekday SB and the highest weekend MVPA duration decreased by 46.9% and 59.8%, respectively( P<0.001)when compared to the highest-risk group. Conclusions:Based on the monitoring data from wearable devices, elderly individuals who reduced their SB time during weekdays and increased their MVPA time on weekends were associated with a lower risk of frailty, especially among women; which providing a new perspective for lifestyle-based intervention strategies for frailty among the elderly.

Objective:To explore the effect of secreted frizzled-related protein 3 (sFRP3) on tau aggregation.Methods:(1) Twelve wild-type C57BL/6J mice and 12 P301S mutant tau transgenic (tau P301S) mice were selected; Western blotting was used to detect the sFRP3 protein expression in the brain tissues; co-immunoprecipitation experiment was conducted to verify endogenous sFRP3 binding to tau; and double immunofluorescent staining was performed to observe whether sFRP3 co-localized with phosphorylated tau. (2) Recombinant human tau (K18) and sFRP3 protein were purified, and pre-formed fibrils (PFFs) containing only K18 or mixed PFFs (containing both sFRP3 and K18) were prepared; His pull-down assay was adopted to verify exogenous purified sFRP3 binding to tau. Aggregation of these two types of PFFs was observed by thioflavin T (ThT) fluorescence,and anti-digestibility of these two types of PFFs was detected by proteinase K (PK) assay. Ultrastructure of two types of PFFs was observed under transmission electron microscope. (3) HEK293 cells stably expressing green fluorescent protein (GFP) and tau repeat domain (GFP-tau RD HEK293) were treated with the two tpyes of PFFs; intracellular tau aggregation was observed by immunofluorescence; intracellular soluble or insoluble component was evaluated by density gradient lysis. SH-SY5Y cells were treated with the two types of PFFs; cell counting kit-8 (CCK-8) assay was used to detect cell viability; Western blotting was used to detect the expressions of apoptosis-related proteins (Bcl-2-associated X protein [Bax] and cleaved caspase-3); double staining with propidium iodide (PI) and Hoechst 33342, and TUNEL were used to detect cell apoptosis. Primary neurons were treated with the two types of PFFs; density of dendritic spines was measured by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) staining; expressions of synaptic proteins, such as synapsin I and vesicle-associated membrane protein 2 (VAMP2), were detected by Western blotting and double immunofluorescent staining. Results:(1) sFRP3 expression in the brain tissues of tau P301S mice was significantly higher than that in wild-type mice (1.10±0.05 vs. 0.79±0.06, P<0.05). In the brain tissues of wild-type mice, endogenous sFRP3 could bind to tau, and in the brain tissues of tau P301S mice, sFRP3 and phosphorylated tau were co-localized. (2) Exogenous tau and sFRP3 could interact with each other. After constant temperature oscillation for approximately 180 minutes, the ThT fluorescent intensity in mixed PFFs was significantly higher than that in K18 PFFs. Remaining proteins of mixed PFFs were significantly increased compared with those of K18 PFFs after the same digestion time of 1 and 2 μg/mL PK (0.77±0.02 vs. 0.67±0.03; 0.52±0.04 vs. 0.33±0.02, P<0.05). The ultrastructure of mixed PFFs was longer and more compact than K18 PFFs. (3) Compared with K18 PFFs, mixed PFFs formed more intracellular tau aggregation points and had more insoluble components (insoluble protein and soluble protein ratio: 0.43±0.04 and 0.92±0.08), with significant differences ( P<0.05). Compared with K18 PFFs, mixed PFFs had significantly decreased SH-SY5Y cell viability (0.44±0.01 vs. 0.24±0.02), significantly up-regulated Bax and cleaved caspase-3 protein expressions (0.71±0.04 vs. 0.87±0.04; 0.60±0.06 vs. 0.88±0.03), significantly increased percentage of apoptotic cells (PI/Hoechst staining: 8.00%±0.49% vs. 18.11%±1.13%; TUNEL staining: 6.62%±0.91% vs. 14.94%±1.32%, P<0.05). Compared with the K18 PFFs group, the mixed PFFs group had significantly decreased density of dendritic spines ([5.7±0.28]/10 μm vs. [2.7±0.29]/10 μm), synapsin I and VAMP2 expressions (0.95±0.02 vs. 0.48±0.04; 0.88±0.03 vs. 0.52±0.06), and average fluorescent intensity of synapsin I and VAMP2 in the primary neurons (7.73±0.70 vs. 2.74±0.34; 6.14±0.60 vs. 2.96±0.54, P<0.05). Conclusion:sFRP3 interacts with tau to promote tau aggregation, and enhance the cytotoxic effect of tau aggregation.

Objective To develop a system for retrieving information from clinical records of Traditional Chinese Medicine(TCM)based on generative large language models(LLMs).Methods Applicational needs of the system were analyzed,and entity types to be retrieved were identified.The functions,workflows,and architecture of the system were designed by combining the automatic retrieval capabilities of LLMs with human-in-the-loop(HITL).The software was developed using such frameworks as vLLM and Node.js.Interaction of multiple commercial/open source LLMs was implemented using OpenAI-compatible interfaces.The quality of information retrieved from LLMs was enhanced by prompt engineering.Results This system supported task allocation,automatic retrieval of structured information,and manual review.To evaluate its performance,the moonshot-v1-8k model was used to retrieve clinical records of TCM before manual edition was performed.Combining large language model pre-annotation with meticulous annotator edits improved accuracy by 26.6％compared to the BERT-BiLSTM-CRF model,and enhanced extraction efficiency by 1.6-fold relative to purely manual methods.Conclusion General generative LLMs can retrieve a wide range of entity information from TCM records with high accuracy and scalability.The design and implementation of this system approach may provide a useful reference for developing other biomedical information retrieval systems.

ObjectiveTo investigate the possible mechanism of action of Xibining Formula （膝痹宁） for cartilage damage in knee osteoarthritis （KOA） through the cyclic guanosine-adenosine monophosphate synthase （cGAS）- stimulator of interferon genes （STING） signaling pathway. MethodsFifty C57BL/6J mice were randomly divided into five groups （10 per group）， sham operation group， KOA model group， low-dose Xibining Formula group， high-dose Xibining Formula group， and high-dose Xibining Formula + agonist group. The KOA models were constructed using the destabilization of the medial meniscus （DMM） method in all groups but the sham surgery group. Two weeks after surgery， the low- and high-dose Xibining Formula groups were administered Xibining Formula at doses of 3.58 g/（kg·d） and 14.32 g/（kg·d） respectively via gavage. The high-dose Xibining Formula + agonist group received 14.32 g/（kg·d） of Xibining Formula via gavage followed by an intraperitoneal injection of Vadimezan （DMXAA） at 25 mg/kg. The sham surgery group and the KOA model group mice were given an equivalent volume of normal saline at 5 ml/（kg·d） via gavage， once daily for four consecutive weeks. Serum levels of tumor necrosis factor-alpha （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6） were measured by ELISA； pathological changes in cartilage tissue were observed using hematoxylin-eosin （HE） staining and Safranin O-Fast Green staining. Pathological changes were scored according to the Mankin scoring system； the levels of cartilage tissue matrix regulation-related indicators such as matrix metalloproteinase 3 （MMP3）， matrix metalloproteinase 13 （MMP13）， a disintegrin and metalloproteinase with thrombospondin motifs 5 （ADAMTS）， type-Ⅱ collagen （CⅡ） and aggregated proteoglycan （Aggrecan）， and also cGAS-STING pathway-related protein and mRNA expression levels were detected by Western blot and qPCR methods. ResultsCompared with the sham surgery group， the KOA model group showed severe cartilage edge destruction， significantly increased Mankin scores， significantly decreased protein and mRNA expression levels of COLⅡ and Aggrecan， and significantly increased protein and mRNA expression levels of cGAS， STING， MMP3， MMP13， and ADAMTS5 （P＜0.01）. Compared with the control group， serum level of IL-6， IL-1β， TNF-α in all the intervented groups decreased （P＜0.01）， while compared with high-dose Xibining Formula group， level of IL-6， IL-1β， and TNF-α in low-dose Xibining Formula group and high-dose Xibining Formula + agonist group increased （P＜0.01）. Compared with the KOA model group， all the intervention groups exhibited alleviated cartilage pathological changes， signi-ficantly reduced Mankin scores， significantly increased protein and mRNA expression levels of COLⅡ and Aggrecan， and significantly decreased protein and mRNA expression levels of cGAS， STING， MMP3， MMP13， and ADAMTS5 （P＜0.01）. Compared with high-dose Xibining Formula group， high-dose Xibining Formula + agonist group showed cartilage edge destruction， significantly increased Mankin scores， significantly decreased protein and mRNA expression levels of COLⅡ and Aggrecan， and increased protein and mRNA expression levels of cGAS， STING， MMP3， MMP13， and ADAMTS5 （P＜0.01）. ConclusionXibining Formula may improve KOA cartilage damage by inhibiting the cGAS-STING signaling pathway， decreasing matrix degradation-related proteins， and elevating matrix composition-related proteins.

AIM:This study aimed to investigate the inhibitory effects and potential mechanisms of cyasterone(CYA)on inflammation and apoptosis of chondrocytes in knee osteoarthritis(KOA).METHODS:A rat model of KOA was established through anterior cruciate ligament transection(ACLT).Rats were randomly divided into 5 groups(n=6 in each group):normal control(NC),ACLT,ACLT+CYA(10 mg/kg),ACLT+CYA+SR9009(BMAL1 inhibitor),and ACLT+CYA+LY294002(PI3K inhibitor).Pathological changes in cartilage were evaluated using hematoxylin-eosin(HE)and safranin O/fast green staining,graded according to the Osteoarthritis Research Society International(OARSI)system.Immunohistochemistry was employed to measure the expression levels of BMAL1,phosphorylated phosphati-dylinositol 3-kinase(p-PI3K),phosphorylated protein kinase B(p-AKT)and phosphorylated nuclear factor-κB(p-NF-κB)in cartilage.An in vitro KOA model was created by stimulating rat chondrocytes with interleukin-1β(IL-1β).Cell vi-ability was assessed using the CCK-8 assay,while enzyme-linked immunosorbent assay(ELISA)was used to quantify pro-inflammatory cytokines(IL-6,IL-1β and TNF-α).Apoptosis was analyzed via flow cytometry,and the protein expression levels of BMAL1,PI3K,p-PI3K,AKT,p-AKT,NF-κB and p-NF-κB were evaluated using Western blot.RESULTS:In vivo,the rats in ACLT group exhibited significant chondrocyte degradation and lacunae formation compared with NC group,confirming the successful establishment of the KOA model.The rats in ACLT+CYA,ACLT+CYA+SR9009 and ACLT+CYA+LY294002 groups showed improved cartilage integrity compared with ACLT group,with reduced OARSI scores(P<0.05),increased BMAL1 expression(P<0.05),and decreased levels of p-PI3K,p-AKT and p-NF-κB(P<0.05).In vitro,the chondrocytes in IL-1β+CYA,IL-1β+CYA+SR9009 and IL-1β+CYA+LY294002 groups exhibited lower levels of IL-6,IL-1β and TNF-α(P<0.05),decreased apoptosis rates(P<0.01),increased BMAL1 protein ex-pression(P<0.05),and reduced p-PI3K/PI3K,p-AKT/AKT and p-NF-κB/NF-κB ratios(P<0.05),compared with IL-1β group.CONCLUSION:Cyasterone alleviates chondrocyte inflammation and apoptosis in KOA by activating BMAL1,which subsequently inhibits the phosphorylation of PI3K/AKT/NF-κB signaling pathway.

Objective:To evaluate the stability of percutaneous screw fixation for minimally invasive treatment of intra-articular calcaneal fractures using three-dimensional finite element analysis.Methods:CT scan was performed on the calcaneus of a normal adult for three-dimensional reconstruction. The DICOM data were imported into Mimics software to establish a model of a Sanders type IIB intra-articular calcaneal fracture. Based on the Essex-Lopresti classification of posterior facet morphology, the model was subdivided into two subtypes: tongue-type and depression-type. The calcaneus was divided into four fragments: sustentaculum tali, posterior tuberosity, anterior process (three points), and posterior articular surface (one surface). Two types of fixation methods, classical lateral anatomical plates and combinations of percutaneous screws, were simulated and performed. A three-dimensional finite element analysis was conducted by applying a stress combination of 420 N on the posterior subtalar articular surface, 200 N on the middle subtalar articular surface, and 300 N at the Achilles tendon insertion point. The maximum displacement and von Mises stress values of each bone fragment and implant were recorded to evaluate the biomechanical stability. For clinical validation, 34 patients with Sanders type IIB calcaneal fractures from Orthopedics Department of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University were treated with percutaneous reduction and screw fixation using the following configurations.Results:Under simulated stress, the A4 group with medial support screws in the tongue-type fracture subgroup demonstrated minimal overall calcaneal displacement (0.22 mm) and internal fixation displacement (0.14 mm). For the depression-type, the B2 group with medial support screws showed lower maximum stress in the calcaneus and internal fixation, at 22.04 MPa and 41.14 MPa, respectively, along with the lowest overall displacement (0.14 mm). The peak stress of all groups of implants remained below the material yield strength. The A4 and B2 protocols were applied to 15 cases of tongue-type calcaneal fractures and 19 cases of collapse-type calcaneal fractures. At the final follow-up The American Orthopaedic Foot & Ankle Society ankle-hindfoot score scale was 86.1±5.82 and 87.2±5.18, respectively, while the visual analog scale for pain was 1.60±1.24 and 1.58±1.02, respectively.Conclusions:Percutaneous screw fixation provided reliable stability for Sanders type IIB calcaneal fractures. The fixation configuration incorporating a medial support screw offers superior biomechanical performance in both tongue-type and depression-type fractures, representing an optimized minimally invasive technique with strong clinical applicability.

Objective:To evaluate the stability of percutaneous screw fixation for minimally invasive treatment of intra-articular calcaneal fractures using three-dimensional finite element analysis.Methods:CT scan was performed on the calcaneus of a normal adult for three-dimensional reconstruction. The DICOM data were imported into Mimics software to establish a model of a Sanders type IIB intra-articular calcaneal fracture. Based on the Essex-Lopresti classification of posterior facet morphology, the model was subdivided into two subtypes: tongue-type and depression-type. The calcaneus was divided into four fragments: sustentaculum tali, posterior tuberosity, anterior process (three points), and posterior articular surface (one surface). Two types of fixation methods, classical lateral anatomical plates and combinations of percutaneous screws, were simulated and performed. A three-dimensional finite element analysis was conducted by applying a stress combination of 420 N on the posterior subtalar articular surface, 200 N on the middle subtalar articular surface, and 300 N at the Achilles tendon insertion point. The maximum displacement and von Mises stress values of each bone fragment and implant were recorded to evaluate the biomechanical stability. For clinical validation, 34 patients with Sanders type IIB calcaneal fractures from Orthopedics Department of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University were treated with percutaneous reduction and screw fixation using the following configurations.Results:Under simulated stress, the A4 group with medial support screws in the tongue-type fracture subgroup demonstrated minimal overall calcaneal displacement (0.22 mm) and internal fixation displacement (0.14 mm). For the depression-type, the B2 group with medial support screws showed lower maximum stress in the calcaneus and internal fixation, at 22.04 MPa and 41.14 MPa, respectively, along with the lowest overall displacement (0.14 mm). The peak stress of all groups of implants remained below the material yield strength. The A4 and B2 protocols were applied to 15 cases of tongue-type calcaneal fractures and 19 cases of collapse-type calcaneal fractures. At the final follow-up The American Orthopaedic Foot & Ankle Society ankle-hindfoot score scale was 86.1±5.82 and 87.2±5.18, respectively, while the visual analog scale for pain was 1.60±1.24 and 1.58±1.02, respectively.Conclusions:Percutaneous screw fixation provided reliable stability for Sanders type IIB calcaneal fractures. The fixation configuration incorporating a medial support screw offers superior biomechanical performance in both tongue-type and depression-type fractures, representing an optimized minimally invasive technique with strong clinical applicability.

AIM:This study aimed to investigate the inhibitory effects and potential mechanisms of cyasterone(CYA)on inflammation and apoptosis of chondrocytes in knee osteoarthritis(KOA).METHODS:A rat model of KOA was established through anterior cruciate ligament transection(ACLT).Rats were randomly divided into 5 groups(n=6 in each group):normal control(NC),ACLT,ACLT+CYA(10 mg/kg),ACLT+CYA+SR9009(BMAL1 inhibitor),and ACLT+CYA+LY294002(PI3K inhibitor).Pathological changes in cartilage were evaluated using hematoxylin-eosin(HE)and safranin O/fast green staining,graded according to the Osteoarthritis Research Society International(OARSI)system.Immunohistochemistry was employed to measure the expression levels of BMAL1,phosphorylated phosphati-dylinositol 3-kinase(p-PI3K),phosphorylated protein kinase B(p-AKT)and phosphorylated nuclear factor-κB(p-NF-κB)in cartilage.An in vitro KOA model was created by stimulating rat chondrocytes with interleukin-1β(IL-1β).Cell vi-ability was assessed using the CCK-8 assay,while enzyme-linked immunosorbent assay(ELISA)was used to quantify pro-inflammatory cytokines(IL-6,IL-1β and TNF-α).Apoptosis was analyzed via flow cytometry,and the protein expression levels of BMAL1,PI3K,p-PI3K,AKT,p-AKT,NF-κB and p-NF-κB were evaluated using Western blot.RESULTS:In vivo,the rats in ACLT group exhibited significant chondrocyte degradation and lacunae formation compared with NC group,confirming the successful establishment of the KOA model.The rats in ACLT+CYA,ACLT+CYA+SR9009 and ACLT+CYA+LY294002 groups showed improved cartilage integrity compared with ACLT group,with reduced OARSI scores(P<0.05),increased BMAL1 expression(P<0.05),and decreased levels of p-PI3K,p-AKT and p-NF-κB(P<0.05).In vitro,the chondrocytes in IL-1β+CYA,IL-1β+CYA+SR9009 and IL-1β+CYA+LY294002 groups exhibited lower levels of IL-6,IL-1β and TNF-α(P<0.05),decreased apoptosis rates(P<0.01),increased BMAL1 protein ex-pression(P<0.05),and reduced p-PI3K/PI3K,p-AKT/AKT and p-NF-κB/NF-κB ratios(P<0.05),compared with IL-1β group.CONCLUSION:Cyasterone alleviates chondrocyte inflammation and apoptosis in KOA by activating BMAL1,which subsequently inhibits the phosphorylation of PI3K/AKT/NF-κB signaling pathway.

Objective:To explore the correlation between weekend moderate-to-vigorous physical activity(MVPA), weekday sedentary behavior(SB)and the risk of frailty in the elderly population monitored by wearable devices, and to provide a scientific basis for lifestyle interventions for frailty in the elderly.Methods:This study was based on the data of the UK Biobank from 2013 to 2015.A cross-sectional study design was adopted, and 33, 212 elderly people aged 60 and above with complete physical activity monitoring data were selected.The Frailty Index(FI)constructed by the deficit accumulation method was used to assess the frailty status.The correlation between the combined effect of weekday SB and weekend MVPA and the frailty status was analyzed, and the differences between genders were explored.Results:There were significant differences in physical activity indicators among the elderly with different frailty statuses.As the degree of frailty increased, the MVPA-related indicators showed a downward trend, while the weekday SB time gradually increased.There were sex differences in physical activity patterns and frailties.Compared with women, men had longer SB time on weekdays, lower metabolic equivalent of weekly MVPA consumption, and higher MVPA time on weekends, but the frailties index of women was slightly higher than that of men.After adjusting for confounding factors, the frailty risks for men and women in the subgroup with the lowest weekday SB and the highest weekend MVPA duration decreased by 46.9% and 59.8%, respectively( P<0.001)when compared to the highest-risk group. Conclusions:Based on the monitoring data from wearable devices, elderly individuals who reduced their SB time during weekdays and increased their MVPA time on weekends were associated with a lower risk of frailty, especially among women; which providing a new perspective for lifestyle-based intervention strategies for frailty among the elderly.

Objective:To explore the effect of secreted frizzled-related protein 3 (sFRP3) on tau aggregation.Methods:(1) Twelve wild-type C57BL/6J mice and 12 P301S mutant tau transgenic (tau P301S) mice were selected; Western blotting was used to detect the sFRP3 protein expression in the brain tissues; co-immunoprecipitation experiment was conducted to verify endogenous sFRP3 binding to tau; and double immunofluorescent staining was performed to observe whether sFRP3 co-localized with phosphorylated tau. (2) Recombinant human tau (K18) and sFRP3 protein were purified, and pre-formed fibrils (PFFs) containing only K18 or mixed PFFs (containing both sFRP3 and K18) were prepared; His pull-down assay was adopted to verify exogenous purified sFRP3 binding to tau. Aggregation of these two types of PFFs was observed by thioflavin T (ThT) fluorescence,and anti-digestibility of these two types of PFFs was detected by proteinase K (PK) assay. Ultrastructure of two types of PFFs was observed under transmission electron microscope. (3) HEK293 cells stably expressing green fluorescent protein (GFP) and tau repeat domain (GFP-tau RD HEK293) were treated with the two tpyes of PFFs; intracellular tau aggregation was observed by immunofluorescence; intracellular soluble or insoluble component was evaluated by density gradient lysis. SH-SY5Y cells were treated with the two types of PFFs; cell counting kit-8 (CCK-8) assay was used to detect cell viability; Western blotting was used to detect the expressions of apoptosis-related proteins (Bcl-2-associated X protein [Bax] and cleaved caspase-3); double staining with propidium iodide (PI) and Hoechst 33342, and TUNEL were used to detect cell apoptosis. Primary neurons were treated with the two types of PFFs; density of dendritic spines was measured by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) staining; expressions of synaptic proteins, such as synapsin I and vesicle-associated membrane protein 2 (VAMP2), were detected by Western blotting and double immunofluorescent staining. Results:(1) sFRP3 expression in the brain tissues of tau P301S mice was significantly higher than that in wild-type mice (1.10±0.05 vs. 0.79±0.06, P<0.05). In the brain tissues of wild-type mice, endogenous sFRP3 could bind to tau, and in the brain tissues of tau P301S mice, sFRP3 and phosphorylated tau were co-localized. (2) Exogenous tau and sFRP3 could interact with each other. After constant temperature oscillation for approximately 180 minutes, the ThT fluorescent intensity in mixed PFFs was significantly higher than that in K18 PFFs. Remaining proteins of mixed PFFs were significantly increased compared with those of K18 PFFs after the same digestion time of 1 and 2 μg/mL PK (0.77±0.02 vs. 0.67±0.03; 0.52±0.04 vs. 0.33±0.02, P<0.05). The ultrastructure of mixed PFFs was longer and more compact than K18 PFFs. (3) Compared with K18 PFFs, mixed PFFs formed more intracellular tau aggregation points and had more insoluble components (insoluble protein and soluble protein ratio: 0.43±0.04 and 0.92±0.08), with significant differences ( P<0.05). Compared with K18 PFFs, mixed PFFs had significantly decreased SH-SY5Y cell viability (0.44±0.01 vs. 0.24±0.02), significantly up-regulated Bax and cleaved caspase-3 protein expressions (0.71±0.04 vs. 0.87±0.04; 0.60±0.06 vs. 0.88±0.03), significantly increased percentage of apoptotic cells (PI/Hoechst staining: 8.00%±0.49% vs. 18.11%±1.13%; TUNEL staining: 6.62%±0.91% vs. 14.94%±1.32%, P<0.05). Compared with the K18 PFFs group, the mixed PFFs group had significantly decreased density of dendritic spines ([5.7±0.28]/10 μm vs. [2.7±0.29]/10 μm), synapsin I and VAMP2 expressions (0.95±0.02 vs. 0.48±0.04; 0.88±0.03 vs. 0.52±0.06), and average fluorescent intensity of synapsin I and VAMP2 in the primary neurons (7.73±0.70 vs. 2.74±0.34; 6.14±0.60 vs. 2.96±0.54, P<0.05). Conclusion:sFRP3 interacts with tau to promote tau aggregation, and enhance the cytotoxic effect of tau aggregation.