BACKGROUND:The local immune microenvironment plays an important regulatory role in the process of bone formation,and the immune system is intricately linked to the skeletal system.OBJECTIVE:To systematically review the promotion of bone regeneration from three aspects:immune cell regulation of microenvironment,regulation of immune response by small extracellular vesicles,and induction of immune response by bone biomaterials,and to elucidate the immune regulatory mechanisms involved in bone regeneration.METHODS:Relevant literature was retrieved from PubMed,CNKI,WanFang Database,and VIP Database,using the search terms of"osteoimmunology,immune microenvironment,small extracellular vesicles,bone regeneration,bone tissue repair,biomaterials,and tissue engineering"in English and Chinese.Repeat and irrelevant literature was screened and removed,and 92 articles that met the criteria were selected for intensive reading and review.RESULTS AND CONCLUSION:Multiple immune cells and bone cells are in the same microenvironment,and immune cells can regulate the differentiation and activity of bone cells,collectively forming an immune microenvironment that affects bone regeneration.Neutrophils can significantly reduce local inflammatory responses in the early stages of bone injury,creating a favorable microenvironment for bone regeneration.M1 macrophages can clear foreign bodies and reduce early inflammatory responses,while M2 macrophages can promote the expression of osteogenic markers and factors,playing an important role in the repair process of bone injury.B cells and T cells can directly or indirectly affect the generation and activity of osteoblasts and osteoclasts,regulate bone metabolism,and promote bone regeneration.Extracellular vesicles of small cells regulate the local immune microenvironment through paracrine secretion,promoting bone formation and angiogenesis at the site of bone injury.The metal ions,surface hydrophilicity,porosity,pore size,surface morphology,and surface roughness on the surface of biomaterials can directly regulate local immune responses,and have anti-inflammatory,angiogenic,and osteogenic effects,thereby accelerating bone regeneration.

BACKGROUND:The local immune microenvironment plays an important regulatory role in the process of bone formation,and the immune system is intricately linked to the skeletal system.OBJECTIVE:To systematically review the promotion of bone regeneration from three aspects:immune cell regulation of microenvironment,regulation of immune response by small extracellular vesicles,and induction of immune response by bone biomaterials,and to elucidate the immune regulatory mechanisms involved in bone regeneration.METHODS:Relevant literature was retrieved from PubMed,CNKI,WanFang Database,and VIP Database,using the search terms of"osteoimmunology,immune microenvironment,small extracellular vesicles,bone regeneration,bone tissue repair,biomaterials,and tissue engineering"in English and Chinese.Repeat and irrelevant literature was screened and removed,and 92 articles that met the criteria were selected for intensive reading and review.RESULTS AND CONCLUSION:Multiple immune cells and bone cells are in the same microenvironment,and immune cells can regulate the differentiation and activity of bone cells,collectively forming an immune microenvironment that affects bone regeneration.Neutrophils can significantly reduce local inflammatory responses in the early stages of bone injury,creating a favorable microenvironment for bone regeneration.M1 macrophages can clear foreign bodies and reduce early inflammatory responses,while M2 macrophages can promote the expression of osteogenic markers and factors,playing an important role in the repair process of bone injury.B cells and T cells can directly or indirectly affect the generation and activity of osteoblasts and osteoclasts,regulate bone metabolism,and promote bone regeneration.Extracellular vesicles of small cells regulate the local immune microenvironment through paracrine secretion,promoting bone formation and angiogenesis at the site of bone injury.The metal ions,surface hydrophilicity,porosity,pore size,surface morphology,and surface roughness on the surface of biomaterials can directly regulate local immune responses,and have anti-inflammatory,angiogenic,and osteogenic effects,thereby accelerating bone regeneration.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Background: Visceral white adipose tissue (vWAT) inflammation is a critical pathology of obesity-caused heart damage and is closely associated with adipocyte endoplasmic reticulum (ER) dysfunction. Serine (or cysteine) peptidase inhibitor, clade A, member 3C (Serpina3c) has been identified as an adipokine with anti-vWAT inflammatory effects. However, it remains unclear whether Serpina3c deficiency promotion of vWAT inflammation involves adipocyte ER dysfunction and whether it further contributes to heart damage in obesity. Methods: Wild type and Serpina3c knockout (Serpina3c–/–) mice were fed a high-fat diet (HFD) for 12 weeks. An adeno-associated virus (AAV) was injected locally into epididymal white adipose tissue (eWAT) of Serpina3c–/– mice to induce eWAT-adipocyte- specific overexpression of Serpina3c (AAV-Serpina3c) or knockdown of hypoxia-inducible factor 1α (AAV-shHIF1α). In vitro experiments were performed in 3T3-L1 adipocytes. Results: Serpina3c–/– mice exhibited more severe eWAT, serum and heart inflammation after HFD feeding. Consistently, these adverse phenotypes were mitigated in AAV-Serpina3c and AAV-shHIF1α mice. Mechanistically, ER oxidoreductase 1α (Ero1α) and protein disulfide isomerase (PDI) family members PDIA3 and PDIA4 were found to be target genes of HIF1α. In the obese mice, Serpina3c deficiency caused adipocyte more hypertrophy, and activated HIF1α-Ero1α/PDI mediated ER overoxidation and ER stress in eWAT. Subsequently, this led to increased adipocyte apoptosis and chemokine production and decreased adiponectin expression, which promoted macrophage infiltration and M1 polarization in eWAT, thus exacerbating eWAT inflammation and ultimately facilitating serum and distal heart inflammation. Conclusion These findings indicate that Serpina3c is a significant regulator of adipocyte ER redox homeostasis, thus highlighting Serpina3c as a potential therapeutic target for obesity-related eWAT inflammation and heart damage.

Objective: To investigate the effects of grain size and immersion dyeing time on the dye penetration depth and color parameters of zirconia, and analyze the dyeing behavior in relation to the material's pore characteristics to provide experimental evidence for developing personalized immersion staining protocols for clinical applications targeting zirconia with different microstructures. Methods: A total of 135 pre-sintered zirconia specimens with three different grain sizes were fabricated using computer aided design/manufacturing technology and divided into three groups (S1, S2, S3; n=45). Randomly select 6 specimens from each group, among which 3 zirconia pre sintered specimens are soaked in 10 mL A2 staining solution for 60 s, dried and sintered, and the other 3 are not treated. Observe the microstructure of the outer surface and bonding surface of the specimen under SEM, and use Image J software to count and measure the grain size. From each group, three randomly selected specimens were subjected to mercury intrusion porosimetry to analyze porosity and pore size distribution. For the remaining specimens, the bottom surface (10 × 10 mm) was designated as the staining surface and immersed in 10 mL of A2 staining liquid. The remaining specimens were stained at six time gradients (10, 20, 30, 60, 90, 120 s). After staining, half of the specimens were sectioned perpendicular to the stained surface and fully sintered to measure the staining penetration depth. The other half were directly fully sintered. A spectrophotometer was used to measure the color parameters (L*, a*, b*) of the stained surface, and the color difference (ΔE00) relative to a standard A2 shade tab was calculated. Results: The average grain sizes (G) for the three groups were GS1=(221.64±62.16) nm, GS2=(197.80±46.72) nm, and GS3=(150.21±42.11) nm; the average porosities (P) were PS1=37.82%, PS2=46.02%, and PS3=47.36%. Both grain size and staining time significantly affected the staining outcome of zirconia (P<0.001), with a significant interaction effect (P<0.001). Staining penetration depth increased with prolonged staining time and decreased grain size (P<0.001). All fully sintered specimens exhibited a perceptible color difference (ΔE00>0.8) compared with the standard A2 shade tab (VITA, USA). Specifically, specimens from group S1 stained for 20 s, group S2 stained for 60 s, and group S3 stained for 10 s exhibited color differences below the clinically acceptable threshold (ΔE00<1.8), meeting clinical thickness requirements. Specimens stained for other time intervals exceeded the clinically acceptable color difference threshold (ΔE00>1.8). Conclusion The porosity of pre-sintered zirconia with different grain sizes varied. Higher porosity correlated with deeper staining penetration. The staining time required to achieve the standard A2 shade differed among zirconia materials with different grain sizes. In clinical applications, the immersion dyeing protocol for zirconia should be optimized based on the grain size and pore characteristics of zirconia with different grain sizes, so as to avoid color deviations caused by improper dyeing time.

Objective The aim of the study is to analyze the incidence patterns and epidemiological characteristics of parasitic and vector-borne diseases in the Minhang and Jinshan districts of Shanghai, and provide evidence-based information for optimizing prevention and control measures. Methods We collected information from epidemic reports and epidemiological investigation forms for cases of parasitic and vector-borne diseases from 2005 to 2024 in Shanghai's Minhang and Jinshan districts. Descriptive epidemiological method were adopted to conduct a comparative analysis of incidence trends, epidemic characteristics, and infection sources. Results A total of 229 cases in 7 categories were reported between 2005 and 2024, with an average annual incidence rate of 0.36/100 000. The average annual incidence rate in Minhang District was significantly higher than that in Jinshan District. The most prevalent diseases were malaria and dengue fever, followed by Japanese encephalitis. Monthly case reports were available, predominantly from June to October, with a peak in July-August. A statistically significant difference was observed between the two districts in case distribution during June-October (P＜0.001), whereas no significant difference was found for July-August (P=0.331). The majority of cases were young men (111/229,48.47%), aged 20-39 years. Migrant workers/farmers constituted the largest occupational group (55/229, 24.02%). Registered residents of other provinces and cities (147/229,64.19%), and the main source of infection was overseas importation (112/229,48.91%). There were no statistically significant differences in gender and household-registration composition between the two districts (P＞0.05). Significant differences existed in age, occupation, and source of infection (P＜0.05). The imported diseases were malaria and dengue fever, with Africa and Southeast Asia being the primary source locations. Malaria was the predominant disease imported from other provinces and cities, with cases having been imported from abroad since 2012. Local infections were mainly Japanese encephalitis, followed by malaria (with the last local case reported in 2010). Cases between 2005 and 2009 were predominantly imported from other provinces and cities. The proportion of cases imported from abroad increased sharply after 2010, particularly in Minhang District. Local infections sometimes arise in Jinshan District, with Japanese encephalitis serving as the primary type. Conclusions Incidence rates of parasitic and vector-borne diseases in Minhang and Jinshan districts have generally remained low. To further reduce this disease burden, it will be necessary to strengthen joint measures for prevention and control, eliminate the environmental risk factors of vector organisms, enhance monitoring and precise control of the environment and inbound personnel to prevent the occurrence and transmission of parasitic and vector-borne diseases.

Objective To investigate the risk factors for pneumonia complicating infectious mononucleosis(IM)in adults and construct a nomogram prediction model.Methods A retrospective analysis was conducted on 198 IM patients admitted to the Second Affiliated Hospital of Air Force Medical University from January 2015 to December 2021.Patients were divided into pneumonia group(n=52)and non-pneumonia group(n=146)based on whether pulmonary infection occurred during hospitalization.The baseline data(age,gender,place of onset,etc.),clinical manifestations(maximum body temperature,lymph node enlargement,splenomegaly,etc.),and inflammatory indicators[white blood cell count(WBC),C-reactive protein(CRP),etc.]were compared between the two groups.Kaplan-Meier curves were plotted to analyze the key indicators affecting the hospital stay of IM patients.Multivariate logistic regression was used to analyze the independent risk factors for pneumonia complicating IM in adults and construct a nomogram prediction model based on the identified risk factors.The predictive efficacy of the model was evaluated using the receiver operating characteristic(ROC)curve and the consistency of the model was assessed using the calibration curve.The fit of the model was evaluated using the Hosmer-Lemeshow test.Additionally,the sensitivity,specificity,and accuracy of the model were assessed using confusion matrix.Results Compared with non-pneumonia group,the pneumonia group had a significantly higher proportion of patients from rural areas,with body mass index(BMI)≥24 kg/m2,smoking history,hepatomegaly,fever duration of≥7 d,as well as increased total hospitalization costs and average daily hospitalization costs,and prolonged hospital stay(P<0.05).The proportion of patients with a history of antibiotic use was lower in the pneumonia group(P<0.05).Kaplan-Meier survival analysis showed that patients from rural areas,with BMI≥24 kg/m2,smoking history,no prophylactic use of antibiotics,fever duration≥7 d,and hepatomegaly had significantly prolonged hospital stays(P<0.05).Multivariate logistic regression analysis revealed that living in a rural area(OR=4.089,P<0.05),hepatomegaly(OR=4.082,P<0.05),and elevated WBC(OR=1.205,P<0.05)were independent risk factors for pneumonia complicating IM in adults,while the prophylactic use of antibiotics(OR=0.142,P<0.05)was an independent protective factor.The area under the ROC curve of the constructed nomogram prediction model was 0.827(95%CI 0.762-0.892),and the slope of the calibration curve was close to 1,and the Hosmer-Lemeshow test showed χ2=5.299,P=0.725,indicating good consistency and fit of the prediction model.The results of the confusion matrix assessment showed that the sensitivity of the model was 0.669(0.624-0.773),the specificity was 0.827(0.724-0.930),and the accuracy was 0.732(0.665-0.793).Conclusion The nomogram prediction model based on place of onset,hepatomegaly,the prophylactic use of antibiotics and WBC has excellent fit and discrimination,providing an effective quantitative tool for prognosis assessment of IM.

Objective To investigate the expression levels of LINC02009 and LOC107984895 in peripheral lymphocytes of patients with atrial fibrillation and their clinical significance.Methods A total of 75 hospitalized patients with atrial fibrillation(50 with persistent atrial fibrillation and 25 with paroxysmal atrial fibrillation)from Kunming First People's Hospital between January 2023 and December 2023 were selected as study subjects,along with 50 normal control patients.Real-time quantitative PCR was used to detect the expression levels of LINC02009 and LOC107984895 in peripheral blood leukocytes of patients with atrial fibrillation.Logistic regression analysis was employed to assess the relationship between expression levels and risk factors for atrial fibrillation,and ROC curves were used to predict the diagnostic cut-off values for LINC02009 and LOC107984895 in diagnosing atrial fibrillation.Results There were statistically significant differences in baseline diseases such as hypertension and coronary heart disease,biochemical indicators such as Cr and BNP,and myocardial remodeling indicators such as LAd and LVEF between the AF(paroxysmal atrial fibrillation and persistent atrial fibrillation)group and the Normal group(P＜0.05).The expression levels of LINC02009 and LOC 107984895 in the plasma of the atrial fibrillation group were significantly higher than those in the control group(P＜0.05)and were negatively correlated with LVEF(P＜0.05).The areas under the curve(AUC)of LINC02009 and LOC 107984895 in predicting atrial fibrillation were 0.967(95％CI:0.938～0.995)and 0.900(95％CI:0.838～0.963),respectively.The optimal cut-off values were 1.985 and 0.915,with sensitivities of 88％and 76％,respectively,and specificities of 94％and 90％,respectively.Conclusion LINC02009 and LOC 107984895 are independent risk factors for atrial fibrillation and have certain predictive value for the occurrence of atrial fibrillation.