BACKGROUND:Studies have shown that platelet-derived growth factor BB can stimulate the proliferation and osteogenic differentiation of mesenchymal stem cells and accelerate the calcification process of osteoblast-like cells.However,its clinical application has problems such as short half-life and easy decomposition.Loading the growth factor onto a suitable biomaterial scaffold can enable its slow and continuous release and maintain an effective concentration,which has become a hot topic in current research.OBJECTIVE:To observe the effect of chitosan/reduced graphene oxide scaffolds loaded with platelet-derived growth factor BB on the repair of alveolar bone defect in rats.METHODS:(1)Chitosan/reduced graphene oxide scaffolds(referred to as CS/rGO scaffolds)and chitosan/reduced graphene oxide scaffolds loaded with different mass concentrations(5,10,15,and 20 mg/L)of platelet-derived growth factor BB(referred to as CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds)were prepared respectively.The five groups of scaffolds were co-cultured with rat periodontal ligament stem cells.The cell proliferation and migration were detected by CCK-8 assay and Transwell chamber assay,respectively,to screen the appropriate growth factor loading mass concentration for subsequent experiments.CS/rGO scaffolds(or extracts)and CS/rGO/PDGF-BB-15 scaffolds(or extracts)were co-cultured with rat periodontal ligament stem cells,and the osteogenic differentiation and angiogenic ability of the cells were detected.(2)The alveolar bone defect model was prepared in front of the bilateral maxillary first molars of 16 SD rats,and the rats were randomly divided into 4 intervention groups:the blank control group did not receive any intervention,the simple scaffold group was implanted with CS/rGO/PDGF-BB-15 scaffold,the control group was implanted with CS/rGO scaffold and rat periodontal ligament stem cell complex,and the experimental group was implanted with CS/rGO/PDGF-BB-15 scaffold and rat periodontal ligament stem cell complex,with 4 rats in each group.Twelve weeks after surgery,the bone repair of the alveolar bone defect was observed by Micro CT scanning and hematoxylin-eosin staining.RESULTS AND CONCLUSION:(1)CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds could promote the proliferation and migration of rat periodontal ligament stem cells.Among them,the CS/rGO/PDGF-BB-15 scaffold had the most significant effect on promoting cell proliferation and migration,and this scaffold was used for subsequent experiments.Compared with the CS/rGO scaffold,the CS/rGO/PDGF-BB-15 scaffold could promote the osteogenic and angiogenic differentiation of rat periodontal ligament stem cells.(2)Micro CT scanning and hematoxylin-eosin staining results showed that the experimental group had the best alveolar bone defect repair effect,and a large amount of new bone tissue and blood vessel formation could be seen.(3)The chitosan/reduced graphene oxide scaffold loaded with platelet-derived growth factor BB can effectively promote the repair of rat alveolar bone defects by promoting the proliferation,migration,angiogenic and osteogenic differentiation of rat periodontal ligament stem cells.

BACKGROUND:Studies have shown that platelet-derived growth factor BB can stimulate the proliferation and osteogenic differentiation of mesenchymal stem cells and accelerate the calcification process of osteoblast-like cells.However,its clinical application has problems such as short half-life and easy decomposition.Loading the growth factor onto a suitable biomaterial scaffold can enable its slow and continuous release and maintain an effective concentration,which has become a hot topic in current research.OBJECTIVE:To observe the effect of chitosan/reduced graphene oxide scaffolds loaded with platelet-derived growth factor BB on the repair of alveolar bone defect in rats.METHODS:(1)Chitosan/reduced graphene oxide scaffolds(referred to as CS/rGO scaffolds)and chitosan/reduced graphene oxide scaffolds loaded with different mass concentrations(5,10,15,and 20 mg/L)of platelet-derived growth factor BB(referred to as CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds)were prepared respectively.The five groups of scaffolds were co-cultured with rat periodontal ligament stem cells.The cell proliferation and migration were detected by CCK-8 assay and Transwell chamber assay,respectively,to screen the appropriate growth factor loading mass concentration for subsequent experiments.CS/rGO scaffolds(or extracts)and CS/rGO/PDGF-BB-15 scaffolds(or extracts)were co-cultured with rat periodontal ligament stem cells,and the osteogenic differentiation and angiogenic ability of the cells were detected.(2)The alveolar bone defect model was prepared in front of the bilateral maxillary first molars of 16 SD rats,and the rats were randomly divided into 4 intervention groups:the blank control group did not receive any intervention,the simple scaffold group was implanted with CS/rGO/PDGF-BB-15 scaffold,the control group was implanted with CS/rGO scaffold and rat periodontal ligament stem cell complex,and the experimental group was implanted with CS/rGO/PDGF-BB-15 scaffold and rat periodontal ligament stem cell complex,with 4 rats in each group.Twelve weeks after surgery,the bone repair of the alveolar bone defect was observed by Micro CT scanning and hematoxylin-eosin staining.RESULTS AND CONCLUSION:(1)CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds could promote the proliferation and migration of rat periodontal ligament stem cells.Among them,the CS/rGO/PDGF-BB-15 scaffold had the most significant effect on promoting cell proliferation and migration,and this scaffold was used for subsequent experiments.Compared with the CS/rGO scaffold,the CS/rGO/PDGF-BB-15 scaffold could promote the osteogenic and angiogenic differentiation of rat periodontal ligament stem cells.(2)Micro CT scanning and hematoxylin-eosin staining results showed that the experimental group had the best alveolar bone defect repair effect,and a large amount of new bone tissue and blood vessel formation could be seen.(3)The chitosan/reduced graphene oxide scaffold loaded with platelet-derived growth factor BB can effectively promote the repair of rat alveolar bone defects by promoting the proliferation,migration,angiogenic and osteogenic differentiation of rat periodontal ligament stem cells.

Objective: To explore the influence of social support and school connectedness on the developmental trajectory of self efficacy in adolescents and analyze its subgroup effects, so as to provide a basis for enhancing adolescents self-efficacy. Methods: Using a cluster random sampling method, 930 first year middle school students from four schools in Xiangxi Autonomous Prefecture, Hunan Province, were selected for three longitudinal surveys in October 2023 (T1), April 2024 (T2), and October 2024 (T3). The General Self-efficacy Scale (GSES), Social Support Scale (SSS), and School Connectedness Scale (SCS) were administered. Latent growth mixture modeling (LGMM) was used to identify different developmental trajectories of self-efficacy in early adolescence. Multivariate Logistic regression was employed to examine the associations of self-efficacy trajectories with social support and school connectedness in adolescents. Results: The developmental trajectory of self-efficacy in adolescents was classified into three categories:category 1 was low efficacy-rapid growth group (53 students, 6.6%), category 2 was moderate efficacy-stable growth group (793 students, 84.1%), and category 3 was high efficacy-rapid decline group (84 students, 9.3%). Using the low efficacy- rapid growth group as the reference, students with higher social support were more likely to belong to the moderate efficacy- stable growth group ( OR=1.06, 95%CI =1.03-1.08) and the high efficacy-rapid decline group ( OR=1.06, 95%CI = 1.03 -1.09), students with higher school connectedness were more likely to belong to the high efficacy-rapid decline group ( OR= 1.10 , 95%CI =1.03-1.18) (all P <0.05). Subgroup analysis revealed significant effects for boarding status (low efficacy-rapid growth group at T1, t =2.10; high efficacy-rapid decline group in social support, t =-2.15) and only child status (moderate efficacy-stable growth group at T2, t =2.05) (all P <0.05). Conclusions The developmental trajectory of self-efficacy in adolescents exhibits group heterogeneity, with boarding status and only child status showing subgroup effects. Enhancing social support and school connectedness can help improve self-efficacy in adolescents.

ObjectiveTo explore the mechanism of action of Cuscutae Semen-Salviae Miltiorrhizae Radix et Rhizoma in the treatment of recurrent spontaneous abortion （RSA） through network pharmacology， molecular docking， and cell experiment verification. MethodsThe Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP） and UniPort databases were used to screen and organize the active ingredients and corresponding targets of Cuscutae Semen-Salviae Miltiorrhizae Radix et Rhizoma. The potential therapeutic targets of RSA were screened in Online Mendelian Inheritance in Man （OMIM）， GeneCards database， DrugBank database， DisGeNET database， and Therapeutic Target Database （TTD）. The potential core targets of Cuscutae Semen-Salviae miltiorrhizae Radix et Rhizoma for treating RSA were further screened by constructing a protein-protein interaction （PPI） network and topological analysis. Meanwhile， the Database for Annotation， Visualization and Integrated Discovery （DAVID） was chosen to perform enrichment analysis on intersection targets. On this basis， AutoDock software was used for molecular docking， and the data were imported into PyMOL software for visualization and composition. Finally， the cell counting kit-8 （CCK-8） experiment， Transwell cell invasion assay， and Western blot were used to detect the effects of serum containing Cuscutae Semen-Salviae miltiorrhizae Radix et Rhizoma on HTR-8/SVneo cells and observe the effects on the interleukin （IL）-6/signal transducer and activator of transcription 3（STAT3） signaling pathway and related proteins. ResultsThrough network pharmacology analysis， a total of 69 active ingredients， 73 potential therapeutic targets， and 17 core targets， including IL-6， IL-10， and STAT3， were collected. The 73 common targets were enriched in 614 Gene Ontology （GO） entries and 57 Kyoto Encyclopedia of Genes and Genomes （KEGG） signaling pathways. The molecular docking results indicated that IL-6 and STAT3 had good binding ability with the main active ingredients， including matrine， cryptotanshinone， and tanshinone Ⅱ_A. The cell experiment results showed that， compared with those of the control group， after 24 hours of treatment with the drug-containing serum， the survival and invasion rates of HTR-8/SVneo cells were significantly increased （P<0.05）， and the expression of IL-6/STAT3 signaling pathway and related proteins IL-10 and c-Myc was significantly elevated （P<0.05）. Moreover， the trend of action in the drug-containing serum group was consistent with that of pathway agonists. ConclusionCuscutae Semen-Salviae miltiorrhizae Radix et Rhizoma may enhance the survival rate and invasive activity of HTR-8/SVneo cells to further prevent and treat RSA by activating the IL-6/STAT3 signaling pathway and upregulating the expression of downstream factors IL-10 and c-Myc in the pathway.

Objective: To explore the dynamic relationship between depressive symptom and non-suicidal self-injury(NSSI) behavior among rural left behind junior high school students, as well as the mediating role of social support, so as to provide a reference for preventing the occurrence of behaviors that endanger the physical and mental health of rural adolescents. Methods: In October 2023, 828 rural left behind junior high school students from four counties and cities in Xiangxi Autonomous Prefecture, namely Luxi County, Huayuan County, Baojing County and Longshan County, were selected by cluster random sampling for a one year follow up investigation (T1:October 2023,T2:April 2024,T3:October 2024). Depressive symptom, NSSI behavior and social support of junior high school students were evaluated by using the Patient Health Questionnaire-9(PHQ-9),Adolescent Non suicidal Self injury Assessment Questionnaire (ANSAQ), and Social Support Scale for University Students(SSSUS). A cross lag panel model was constructed to analyze the dynamic relationship between depression symptom and NSSI behavior, as well as the longitudinal mediating role of social support. Results: The levels of depressive symptoms(T1-T3:150.00±5.88，14.29±7.52，13.97±6.70) and NSSI behavior (T1-T3:6.91±4.65，6.10±3.92，4.79±3.51) of rural left behind junior high school students both showed downward trends ( F =13.41, η 2=0.02; F =50.49, η 2=0.06), the level of social support (59.17±14.68，62.27±15.36，61.82±15.90) showed an upward trend ( F =20.94, η 2=0.03), and the depressive symptom and NSSI behavior of girls were higher than those of boys ( F =19.91, η 2=0.02; F =4.57, η 2=0.01)(all P <0.05). The positive predictive relationships between depressive symptom and NSSI behavior among rural left behind junior high school students [depressive symptom of T1 positively predicted NSSI behavior of T2 and T3 ( β =0.10, 0.16); depressive symptom of T2 positively predicted NSSI behavior of T3 ( β =0.14), all P <0.01]. Social support during the T2 period played a partial mediating role between depressive symptom in T1 and NSSI in T3, with a mediating effect of 0.02 (95% CI =0.01-0.17, P <0.05). Conclusions Depressive symptom positively predict the occurrence of NSSI behavior among rural left behind junior high school students. Social support is an important mediating factor in alleviating the influence of depressive symptoms on the occurrence of NSSI behavior. It should prevent and reduce the occurrence of depression symptoms and NSSI behavior by improving the social support level of rural left behind junior high school students.

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic