Organ transplantation is an effective alternative treatment for patients with end-stage organ failure. However, the shortage of donor organs has limited the widespread application of clinical transplantation. In recent years, breakthroughs in CRISPR-Cas9 gene editing technology have overcome the barrier of hyperacute rejection in xenotransplantation, offering a potential solution to the organ shortage crisis. Rejection remains a critical factor affecting graft survival. Antigen-presenting cells play a vital role in the initiation and progression of rejection and immune regulation in xenotransplantation. Therefore, in-depth investigation into the role of antigen-presenting cells in xenotransplantation is of great significance. This article summarizes the roles and therapeutic strategies of professional antigen-presenting cells, including macrophages, dendritic cells and B cells in xenotransplantation, aiming to provide insights for future research on immune regulation mechanisms in this field.

BACKGROUND:Ossification of the ligamentum flavum was previously considered to be rare in the population.As research has progressed,its incidence rate is increasing gradually,which has aroused the interest of a large number of researchers. OBJECTIVE:To visualize and analyze the research results on ossification of the ligamentum flavum from the Web of Science Core Collection since 1999 using bibliometric methods,and to review the research history of ossification of the ligamentum flavum,highlighting important literature,summarizing research hotspots,and providing ideas for researchers to find research directions. METHODS:Using the Web of Science Core Collection as the data source,relevant papers on ossification of the ligamentum flavum were searched and screened.VOSviewer 1.6.19 and CiteSpace 6.2.R6 were used to conduct the visual analysis of annual publication volume,research countries,institutions,citations,journals,authors,and keywords. RESULTS AND CONCLUSION:(1)A total of 347 papers were included.Since 1999,the number of published papers has increased in a spiral pattern.China's research started later than Japan's,but the number of publications has come up later,with Peking University being the institution with the most publications,and Prof.Chen Zhongqiang from Peking University being the scholar with the most publications.(2)Five of the 10 most frequently cited publications were related to the surgical treatment of the disease.(3)Excluding keywords directly related to the research topic and synthetically analyzing frequencies and betweenness centralities of key words,terms such as"thoracic myelopathy,""dural ossification,""minimally invasive surgery,"and"ossification of the posterior longitudinal ligament"occupied a central position in this field.(4)Keywords clustering analysis showed that clinical manifestations and surgical treatment of ossification of the ligamentum flavum accounted for a large proportion of study.(5)The timeline and burst analysis of keywords revealed that"minimally invasive surgery"appeared as a keyword around 2015,with the highest burst strength and the latest burst start time,and began to receive extensive attention from researchers in 2019.The burst of the keyword"dural ossification"has not yet ended.(6)Surgical treatment for ossification of the ligamentum flavum has been at the forefront of research.Development and research of minimally invasive surgery and research on dural ossification secondary to ossification of the ligamentum flavum are both current research hotspots and possible future research trends.

BACKGROUND:Polylactic acid(PLA)has good biocompatibility and a controllable degradation rate and is currently widely used in biomedical engineering.However,PLA has shortcomings such as low mechanical strength and insufficient biological activity,which limits its further application in bone tissue engineering. OBJECTIVE:To construct polylactic acid/polydopamine/tantalum(PLA/PDA/Ta)bone tissue engineering scaffolds,and explore their biosafety and in vitro osteogenesis. METHODS:A PLA scaffold with a porous structure was prepared through liquid crystal display light-curing technology.PLA/PDA scaffolds and PLA/PDA/Ta scaffolds were prepared by soaking PLA scaffolds in dopamine solution and dopamine-tantalum nanoparticle solution,respectively.The microstructure and water contact angle of scaffolds were characterized.MC3T3-E1 cells were co-cultured with PLA,PLA/PDA,and PLA/PDA/Ta scaffolds,respectively,and CCK-8 assay and live/dead cell staining were performed.After osteogenic differentiation,alkaline phosphatase,alizarin red staining,and osteogenic gene detection were performed. RESULTS AND CONCLUSION:(1)The scanning electron microscope results exhibited that the three kinds of prepared scaffolds had an interconnected porous three-dimensional structure,and the average pore diameter was 200 μm.The water contact angle of PLA/PDA/Ta scaffolds was lower than that of PLA and PLA/PDA scaffolds(P<0.05).(2)CCK-8 assay showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote cell proliferation(P<0.05).Live/dead cell staining showed good cell proliferation in the three groups.(3)Alkaline phosphatase and alizarin red staining showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote the expression of alkaline phosphatase and the formation of mineralized nodules.RT-qPCR showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could enhance the mRNA expression of cell bone morphogenetic protein,Runx-2,and type I collagen(P<0.05,P<0.01).(4)The results showed that the PLA/PDA/Ta scaffold had excellent osteogenic activity and the ability to promote cell proliferation.

BACKGROUND:Rheumatoid arthritis is an inflammatory disease.Many studies have shown that wogonin has a good anti-inflammatory effect on rheumatoid arthritis,but its exact efficacy and specific mechanism of action remain to be clarified. OBJECTIVE:To investigate the mechanism of wogonin ameliorating joint inflammation by regulating endoplasmic reticulum stress pathway in rats with collagen-induced arthritis. METHODS:(1)At the animal level:Female Wistar rats were divided into healthy control group,arthritis model group and wogonin treatment group.Rat models of arthritis in the latter two groups were established by subcutaneous injection of bovine type Ⅱ collagen and adjuvant.In the wogonin group,wogonin was given by gavage for 28 consecutive days after modeling.During this period,the rats in each group were weighed,and arthritis score and ankle swelling were measured every 7 days.After the experiment,the pathological changes of the joint were observed,the mRNA and protein levels of endoplasmic reticulum stress pathway GRP78 and CHOP were detected by qRT-PCR,western blot,and immunohistochemistry.(2)At the cellular level,cell counting kit-8 was used to detect the cytotoxic effect of wogonin on fibroblast-like synoviocytes from rats with collagen-induced arthritis.The fibroblast-like synoviocytes induced by thapsigargin were treated with different concentrations of wogonin.The levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant were detected by ELISA,and the intracellular reactive oxygen species in each group were determined by DCFH-DA probe method.The mRNA and protein levels of GRP78,IRE1α,XBP1s and CHOP were detected by qRT-PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the healthy control group,arthritis index score and ankle swelling degree in the arthritis model group were increased(P<0.01),synovial hyperplasia,inflammatory cell infiltration,cartilage destruction and bone erosion were observed in pathological sections,and the mRNA and protein expressions of GRP78 and CHOP in the ankle were significantly increased(P<0.01),which were mainly located in synovial tissue and articular surface.Compared with the arthritis model group,the arthritis index score and ankle swelling degree in the wogonin treatment group were decreased(P<0.05),synovial hyperplasia and the number of inflammatory cells were decreased,cartilage destruction and bone erosion were alleviated,the mRNA and protein expression levels of GRP78 and CHOP in the ankle were decreased(P<0.05),particularly in synovial tissue and on the articular surface.There was no significant difference in body mass among the three groups(P>0.05).In the cell experiment,200 μmol/L wogonin significantly reduced the survival rate of fibroblast-like synoviocytes(P<0.01).Compared with the blank control group,the levels of interleukin-1β,tumor necrosis factor-α,content of reactive oxygen species,and mRNA and protein expression of GRP78,IRE1α,XBP1s,and CHOP in the thapsigargin group were significantly increased(P<0.05);compared with the thapsigargin group,50 and 100 μmol/L wogonin significantly reduced the levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant(P<0.05,P<0.01),and 100 μmol/L wogonin significantly reduced the content of reactive oxygen species(P<0.01)and down-regulated the mRNA and protein expression levels of GRP78,IRE1α,XBP1s and CHOP(all P<0.05).These results suggest that wogonin can effectively alleviate joint inflammatory responses in rats with collagen-induced arthritis,and the endoplasmic reticulum stress pathway may be the key target of its intervention.

BACKGROUND:Extracellular vesicles are secreted into the extracellular milieu by a wide range of cell types,including tumor cells,under different physiological and pathophysiological conditions,where a wide range of biological signals and cell-to-cell signaling exists.Tumor-derived extracellular vesicles may exacerbate cancer progression,survival,invasion,and promote angiogenesis. OBJECTIVE:To review the research progress of extracellular vesicles in the diagnosis and treatment of oral squamous cell carcinoma. METHODS:Literature search was performed by the first author in PubMed,WanFang,CNKI and other databases with the keywords"EVs,oral squamous cell carcinoma,diagnosis and treatment,biopsy,tissue engineering"in Chinese and English.Finally,63 articles were included for analysis. RESULTS AND CONCLUSION:(1)In oral squamous carcinoma saliva biopsies,extracellular vesicles play a crucial role in the progression of oral squamous cell carcinoma by acting as an information transfer tool between tumor cells and the surrounding microenvironment,carrying a wide range of biomolecules including soluble proteins,lipids,DNA,and RNA.These tiny vesicles not only play a key role in tumor growth and spread,but also provide important information about the biological properties of the tumor.(2)Saliva biopsy,as a non-invasive diagnostic method,can open up new possibilities for early diagnosis and targeted treatment of oral squamous cell carcinoma by analyzing the extracellular vesicles therein.(3)It has been found that bioactive molecules,such as microRNAs(miRNAs)and specific proteins,contained within extracellular vesicles can serve as biomarkers for oral squamous carcinoma and improve the accuracy of early diagnosis.Specific proteins in extracellular vesicles such as EHD2,CAVIN1,PF4V1,and CXCL7 show potential as novel predictive biomarkers.(4)In addition,this paper highlights the potential application of extracellular vesicles in the treatment of oral squamous carcinoma.Through engineering modifications,extracellular vesicles can serve as a new generation of nanoscale drug delivery systems to enhance the efficiency and specificity of targeted tumor therapy.(5)Future studies will further explore the effect and mechanism of extracellular vesicles in oral squamous cell carcinoma,which is expected to improve patients'survival and quality of life.

BACKGROUND:In recent years,numerous studies have shown that autophagy and mitophagy play an important role in the regulation of bone metabolism.Under non-physiological conditions,mitophagy breaks the balance of bone metabolism and triggers metabolism disorders,which affect osteoblasts,osteoclasts,osteocytes,chondrocytes,bone marrow mesenchymal stem cells,etc. OBJECTIVE:To summarize the mechanism of mitophagy in regulating bone metabolic diseases and its application in clinical treatment. METHODS:PubMed,Web of Science,CNKI,WanFang and VIP databases were searched by computer using the keywords of"mitophagy,bone metabolism,osteoblasts,osteoclasts,osteocytes,chondrocytes,bone marrow mesenchymal stem cells"in English and Chinese.The search time was from 2008 to 2023.According to the inclusion criteria,90 articles were finally included for review and analysis. RESULTS AND CONCLUSION:Mitophagy promotes the generation of osteoblasts through SIRT1,PINK1/Parkin,FOXO3 and PI3K signaling pathways,while inhibiting osteoclast function through PINK1/Parkin and SIRT1 signaling pathways.Mitophagy leads to bone loss by increasing calcium phosphate particles and tissue protein kinase K in bone tissue.Mitophagy improves the function of chondrocytes through PINK1/Parkin,PI3K/AKT/mTOR and AMPK signaling pathways.Modulation of mitophagy shows great potential in the treatment of bone diseases,but there are still some issues to be further explored,such as different stages of drug-activated mitophagy,and the regulatory mechanisms of different signaling pathways.

BACKGROUND:The diabetic microenvironment can cause excessive M1 polarization of macrophages,and this hyperglycemic inflammatory state can inhibit osteogenic differentiation of bone marrow mesenchymal stem cells,thus affecting the healing of diabetic bone defects.Studies have indicated that mogroside V possesses anti-inflammatory,antioxidant,and hypoglycemic properties.However,its potential to modulate M1 polarization of macrophages and osteogenic differentiation of bone marrow mesenchymal stem cells under high glucose and inflammatory condition remains unclear. OBJECTIVE:To explore the effect of mogroside V on regulating M1 macrophage polarization and its effect on osteogenic differentiation of bone marrow mesenchymal stem cells under high glucose and inflammatory condition. METHODS:Murine diabetic models were established using C57BL/6 mice.Bone marrow-derived macrophages were isolated from tibia and fibula of normal and diabetic mice,and cultured in low-glucose and high-glucose media.Then M1 polarization of bone marrow-derived macrophages was induced using lipopolysaccharide and interferon-γ.Bone marrow-derived macrophages were treated with 160,320,and 640 μmol/L mogroside V.Flow cytometry was employed to determine the proportion of F4/80+CD86+cells.qRT-PCR was utilized to assess mRNA expression levels of inducible nitric oxide synthase,interleukin 1β,and interleukin 6.ELISA was employed to evaluate tumor necrosis factor-α secretion in bone marrow-derived macrophage supernatants.Bone marrow mesenchymal stem cells were isolated from tibia and fibula of C57BL/6 suckling mice,and induced osteogenic differentiation using low-or high-glucose osteogenic induction medium.Bone marrow mesenchymal stem cells were treated with M1 macrophage-conditioned mediums with or without 320 μmol/L mogroside V in osteogenic differentiation process.qRT-PCR was employed to assess the mRNA expression of alkaline phosphatase,Runt-related factor 2,osteocalcin,and osteopontin on day 14 after osteogenic induction.Alizarin red staining and quantitative analysis were conducted to evaluate calcium deposition on day 21 after osteogenic induction. RESULTS AND CONCLUSION:(1)Flow cytometry results showed that with the treatment of 320 and 640 μmol/L mogroside V,the proportion of F4/80+CD86+bone marrow-derived macrophages was significantly lower than that in the high-glucose control group(P<0.05).(2)qRT-PCR results showed that with the treatment of 160,320,and 640 μmol/L mogroside V,the mRNA expression levels of inducible nitric oxide synthase and interleukin 6 were significantly lower than that in the high-glucose control group(P<0.05).With the treatment of 320 and 640 μmol/L mogroside V,the mRNA expression level of interleukin 1β was significantly lower than that in the high-glucose control group(P<0.05).(3)ELISA results exhibited that with the treatment of 160,320,and 640 μmol/L mogroside V,the tumor necrosis factor-α secretion level was significantly lower than that in the high-glucose control group(P<0.05).(4)With the treatment of 320 μmol/L mogroside V,calcium salt deposition was increased in bone marrow mesenchymal stem cells under high glucose and inflammatory conditions(P<0.05),and the mRNA relative expression levels of alkaline phosphatase,Runt-related factor 2,and osteopontin were increased(P<0.05).These findings indicate that mogroside V can promote osteogenic differentiation of bone marrow mesenchymal stem cells by inhibiting the M1 polarization of bone marrow-derived macrophages under high glucose and inflammatory conditions and reducing the generation of inflammatory factors.

BACKGROUND:Spleen has the functions of blood storage,hematopoiesis,and immunity.With the increase of age,the structural degeneration and functional decline of spleen lead to the impairment of immune system function,thus accelerating the aging process of the body.The treatment of spleen aging in tree shrews with highly active umbilical cord mesenchymal stem cells has not been reported. OBJECTIVE:To explore the intervention effect and mechanism of highly active umbilical cord mesenchymal stem cells on spleen aging in tree shrews. METHODS:Highly active umbilical cord mesenchymal stem cells were isolated,cultured,and obtained from the umbilical cord tissue of newborn tree shrews by caesarean section.The differentiation abilities of adipogenesis,osteogenesis,and chondrogenesis were detected by three-line differentiation kit.Cell cycle and surface markers were detected by flow cytometry.The second generation of highly active umbilical cord mesenchymal stem cells were transfected with Genechem Green Fluorescent Protein with infection complex values of 100,120,140,160,180,and 200,respectively,to screen the best transfection conditions.After transfection,the fourth generation of highly active umbilical cord mesenchymal stem cells was injected into the tail vein of tree shrews in the elderly treatment group.The young control group and the aged model group were not given special treatment.After 4 months of treatment,the spleen tissue was taken and the structure of the spleen was observed by hematoxylin-eosin staining.β-Galactosidase staining was used to detect the activity of aging-related galactosidase.Immunohistochemical staining was used to detect the expression levels of p21 and p53 proteins.Ki67 and PCNA immunofluorescence staining was used to detect cell proliferation activity.Immunofluorescence staining was used to detect the expression levels of spleen autophagy protein molecules Beclin 1 and APG5L/ATG5.Reactive oxygen species fluorescence staining was used to detect the content of reactive oxygen species in spleen tissue.CD3 immunofluorescence staining was used to detect the change of the proportion of total T lymphocytes.The secretion levels of interleukin 1β and transforming growth factor β1 in spleen were detected by enzyme linked immunosorbent assay.The distribution of highly active umbilical cord mesenchymal stem cells labeled with green fluorescent protein in spleen tissue was observed by DAPI double staining of nucleus. RESULTS AND CONCLUSION:(1)Highly active umbilical cord mesenchymal stem cells grew in a short spindle shape with fish-like growth,with a large proportion of G0/G1 phase,and had the potential to differentiate into adipogenesis,osteogenesis,and chondrogenesis.(2)Multiplicity of infection=140 and transfection for 72 hours were the best conditions for labeling tree shrews highly active umbilical cord mesenchymal stem cells with Genechem Green Fluorescent Protein.(3)Compared with the aged model group,in the aged treatment group,the spleen tissue cells of tree shrews were arranged closely,and the area of white pulp was increased(P<0.01);the boundary between red pulp and white pulp was clear;the proportion of germinal centers did not show statistically significant difference(P>0.05).The activity level of galactosidase related to spleen tissue aging was decreased(P<0.001),and the expression levels of aging protein molecules p21 and p53 were down-regulated(P<0.001).The expression levels of proliferation-related molecules Ki67 and PCNA were up-regulated(P<0.001,P<0.05);expression levels of autophagy-related molecules Beclin 1 and APG5L/ATG5 were up-regulated(P<0.001),and the content of reactive oxygen species decreased(P<0.001),and the proportion of CD3+T cells increased(P<0.05).The secretion level of interleukin 1β in the aging-related secretion phenotype decreased(P<0.001);no significant difference was found in transforming growth factor β1 level(P>0.05).Compared with the young control group,the above indexes were significantly different in the elderly treatment group(P<0.05).(4)Green fluorescent cells labeled with green fluorescent protein were observed in spleen tissue of tree shrews the elderly treatment group by frozen tissue section observation.The results show that intravenous infusion of highly active umbilical cord mesenchymal stem cells can migrate to spleen tissue,inhibit the production of reactive oxygen species,down-regulate the expression of aging-related proteins,induce autophagy,promote cell proliferation,reduce chronic inflammation,and then improve the structure and function of spleen tissue.

BACKGROUND:Our previous study found that Modified Erxian Pill could alleviate inflammation in collagen-induced arthritis rats,but its mechanism needs to be further verified. OBJECTIVE:To analyze the components absorbed in the blood of Modified Erxian Pill,and observe the effect of the drug-containing serum of Modified Erxian Pill on pyroptosis of J774A.1 macrophages. METHODS:(1)Analysis of components absorbed in the blood of Modified Erxian Pill:Ultra-high performance liquid chromatography-high resolution mass spectrometry was used to detect and identify Modified Erxian Pill and its components absorbed in the blood.(2)Effect of the drug-containing serum of Modified Erxian Pill on pyroptosis of J774A.1 macrophages:Molecular docking technology was used to initially verify the sesquiterpenoids and NLRP3 in components absorbed in the blood of Modified Erxian Pill.J774A.1 macrophages were randomly divided into blank control group,lipopolysaccharide+adenosine triphosphate group,and lipopolysaccharide+adenosine triphosphate+Modified Erxian Pill with low(2.5%),medium(5%),and high(10%)dose groups.The release of lactate dehydrogenase in the cell supernatant of each group was detected according to the kit instructions.The levels of interleukin-1β and interleukin-18 in cell supernatant were detected in each group by ELISA.The cell membrane damage was detected by Hoechst/PI staining.The expression levels of NLRP3,Caspase-1,GSDMD,and GSDMD-N protein in the cells of each group were detected by western blot assay. RESULTS AND CONCLUSION:(1)A total of 32 active components of Modified Erxian Pill were identified,and 21 components entered the blood.The main components into blood included a variety of sesquiterpenoids.(2)Molecular docking results showed that 3-O-Acetyl-13-deoxyphomenone,Incensol oxide,Atractylenolide III,Rupestonic acid,and 3,7-Dihydroxy-9,11-eremophiladien-8-one had good binding activity with NLRP3.(3)Compared with the blank control group,lactate dehydrogenase activity and the expression levels of interleukin-1β and interleukin-18 were significantly increased in cell supernatant of lipopolysaccharide+adenosine triphosphate group(P<0.001).Hoechst/PI staining showed that the number of PI-positive cells was significantly increased.After the intervention of lipopolysaccharide+adenosine triphosphate+Modified Erxian Pill group,all of them showed different degrees of reduction.(4)Compared with the blank control group,NLRP3,Caspase-1,GSDMD,and GSDMD-N protein expression levels were significantly increased in the lipopolysaccharide+adenosine triphosphate group(P<0.05).Compared with lipopolysaccharide+adenosine triphosphate group,the protein expressions of NLRP3,Caspase-1,GSDMD,and GSDMD-N were significantly decreased in the lipopolysaccharide+adenosine triphosphate+Modified Erxian Pill group(P<0.05),and had a certain dose dependence.These findings verify that the drug-containing serum of Modified Erxian Pill may inhibit the pyroptosis of J774A.1 macrophages by regulating the NLRP3/Caspase-1/GSDMD pathway.

Objective: To explore the associations of moderate to vigorous intensity physical activity (MVPA) and sedentary behavior (SB) among primary and secondary school students and their parents, so as to provide a scientific basis for formulating targeted physical activity promotion strategies for children and adolescents. Methods: From 2021 to 2022, basic information and 24 h movement behaviors of 2 484 pairs of students and their parents were collected from five primary and secondary schools in Haizhu District, Guangzhou City, with a convenient sampling combining with cluster sampling method. Component regression models were constructed to analyze the relationship between parental MVPA, SB and primary and secondary school students MVPA and SB, and a component isochronous substitution model was used to explore the effects of mutual substitution between parental MVPA, residual components (time use components other than SB during the 24 h period), and SB on the behavioral activities of MVPA and SB in primary and secondary school students. Results: Parental MVPA and SB of students in grade 1 to 3 were positively correlated with both students MVPA and SB ( β=0.06, 0.12, P <0.01). The component isochronous substitution model showed that substituting 10 and 20 minutes of MVPA for SB by parents in grade 1 to 3 was associated with an increase in MVPA of students, and substituting 10 and 20 minutes of residual ingredients for SB was associated with a decrease in SB of students, with mean changes of 0.8 (95% CI =0.4-1.2) and 1.4 (95% CI =0.7-2.2) and -1.4 (95% CI =-1.7 to -1.1) and -2.9 (95% CI =-3.4 to -2.3)( P <0.05). No statistically significant associations were observed between parents of students in grades 4 to 6 and 7 to 9 and students physical activity and sedentary behaviour ( P >0.05). Conclusions Parents of students in grades 1 to 3 increases MVPA and decrease SB are beneficial to increase MVPA and decrease SB of students. Parents could promote physical activity among primary and secondary school students, and the intervention gateway should be advanced, with the low grades as the optimal intervention period.